Feature: Add append to array

Adds the ability to append a value to an array instead of having to
know the index of the values within the array.

Resolves: #17

docs/mkdocs/search_index.json

@@ -57,7 +57,7 @@
         }, 
         {
             "location": "/write/", 
-            "text": "yaml w \nyaml_file|json_file\n \npath\n \nnew value\n\n\n\n\n\nThis command can take a json file as input too, and will output yaml unless specified to export as json (-j)\n\n\nTo Stdout\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.c cat\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n\n\n\n\nFrom STDIN\n\n\ncat sample.yaml | yaml w - b.c blah\n\n\n\n\nAdding new fields\n\n\nAny missing fields in the path will be created on the fly.\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.d[0] \nnew thing\n\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n  d:\n    - new thing\n\n\n\n\nUpdating files in-place\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w -i sample.yaml b.c cat\n\n\n\n\nwill update the sample.yaml file so that the value of 'c' is cat.\n\n\nUpdating multiple values with a script\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n  e:\n    - name: Billy Bob\n\n\n\n\nand a script update_instructions.yaml of:\n\n\nb.c: 3\nb.e[0].name: Howdy Partner\n\n\n\n\nthen\n\n\nyaml w -s update_instructions.yaml sample.yaml\n\n\n\n\nwill output:\n\n\nb:\n  c: 3\n  e:\n    - name: Howdy Partner\n\n\n\n\nAnd, of course, you can pipe the instructions in using '-':\n\n\ncat update_instructions.yaml | yaml w -s - sample.yaml\n\n\n\n\nValues starting with a hyphen (or dash)\n\n\nThe flag terminator needs to be used to stop the app from attempting to parse the subsequent arguments as flags:\n\n\nyaml w -- my.path -3\n\n\n\n\nwill output\n\n\nmy:\n  path: -3", 
+            "text": "yaml w \nyaml_file|json_file\n \npath\n \nnew value\n\n\n\n\n\nThis command can take a json file as input too, and will output yaml unless specified to export as json (-j)\n\n\nTo Stdout\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.c cat\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n\n\n\n\nFrom STDIN\n\n\ncat sample.yaml | yaml w - b.c blah\n\n\n\n\nAdding new fields\n\n\nAny missing fields in the path will be created on the fly.\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.d[0] \nnew thing\n\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n  d:\n    - new thing\n\n\n\n\nAppending value to an array field\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n  d:\n    - new thing\n    - foo thing\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.d[+] \nbar thing\n\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n  d:\n    - new thing\n    - foo thing\n    - bar thing\n\n\n\n\nUpdating files in-place\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w -i sample.yaml b.c cat\n\n\n\n\nwill update the sample.yaml file so that the value of 'c' is cat.\n\n\nUpdating multiple values with a script\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n  e:\n    - name: Billy Bob\n\n\n\n\nand a script update_instructions.yaml of:\n\n\nb.c: 3\nb.e[0].name: Howdy Partner\n\n\n\n\nthen\n\n\nyaml w -s update_instructions.yaml sample.yaml\n\n\n\n\nwill output:\n\n\nb:\n  c: 3\n  e:\n    - name: Howdy Partner\n\n\n\n\nAnd, of course, you can pipe the instructions in using '-':\n\n\ncat update_instructions.yaml | yaml w -s - sample.yaml\n\n\n\n\nValues starting with a hyphen (or dash)\n\n\nThe flag terminator needs to be used to stop the app from attempting to parse the subsequent arguments as flags:\n\n\nyaml w -- my.path -3\n\n\n\n\nwill output\n\n\nmy:\n  path: -3", 
             "title": "Write/Update"
         }, 
         {
@@ -75,6 +75,11 @@
             "text": "Any missing fields in the path will be created on the fly.  Given a sample.yaml file of:  b:\n  c: 2  then  yaml w sample.yaml b.d[0]  new thing   will output:  b:\n  c: cat\n  d:\n    - new thing", 
             "title": "Adding new fields"
         }, 
+        {
+            "location": "/write/#appending-value-to-an-array-field", 
+            "text": "Given a sample.yaml file of:  b:\n  c: 2\n  d:\n    - new thing\n    - foo thing  then  yaml w sample.yaml b.d[+]  bar thing   will output:  b:\n  c: cat\n  d:\n    - new thing\n    - foo thing\n    - bar thing", 
+            "title": "Appending value to an array field"
+        }, 
         {
             "location": "/write/#updating-files-in-place", 
             "text": "Given a sample.yaml file of:  b:\n  c: 2  then  yaml w -i sample.yaml b.c cat  will update the sample.yaml file so that the value of 'c' is cat.", 

docs/sitemap.xml

@@ -4,7 +4,7 @@
     
     <url>
      <loc>/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -12,7 +12,7 @@
     
     <url>
      <loc>/read/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -20,7 +20,7 @@
     
     <url>
      <loc>/write/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -28,7 +28,7 @@
     
     <url>
      <loc>/create/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -36,7 +36,7 @@
     
     <url>
      <loc>/convert/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -44,7 +44,7 @@
     
     <url>
      <loc>/merge/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     

docs/write/index.html

@@ -250,6 +250,13 @@
     Adding new fields
   </a>
   
+</li>
+      
+        <li class="md-nav__item">
+  <a href="#appending-value-to-an-array-field" title="Appending value to an array field" class="md-nav__link">
+    Appending value to an array field
+  </a>
+  
 </li>
       
         <li class="md-nav__item">
@@ -355,6 +362,13 @@
     Adding new fields
   </a>
   
+</li>
+      
+        <li class="md-nav__item">
+  <a href="#appending-value-to-an-array-field" title="Appending value to an array field" class="md-nav__link">
+    Appending value to an array field
+  </a>
+  
 </li>
       
         <li class="md-nav__item">
@@ -436,6 +450,28 @@
     - new thing
 </code></pre>
 
+<h3 id="appending-value-to-an-array-field">Appending value to an array field<a class="headerlink" href="#appending-value-to-an-array-field" title="Permanent link">&para;</a></h3>
+<p>Given a sample.yaml file of:</p>
+<pre><code class="yaml">b:
+  c: 2
+  d:
+    - new thing
+    - foo thing
+</code></pre>
+
+<p>then</p>
+<pre><code class="bash">yaml w sample.yaml b.d[+] &quot;bar thing&quot;
+</code></pre>
+
+<p>will output:</p>
+<pre><code class="yaml">b:
+  c: cat
+  d:
+    - new thing
+    - foo thing
+    - bar thing
+</code></pre>
+
 <h3 id="updating-files-in-place">Updating files in-place<a class="headerlink" href="#updating-files-in-place" title="Permanent link">&para;</a></h3>
 <p>Given a sample.yaml file of:</p>
 <pre><code class="yaml">b: