Add support for inline warning control

This update adds support for per paragraph message silencing
(`ignore`), turning off messages (`disable`) and turning on messages
(`enable`) through HTML comment markers in markdown.

For example:

```md
<!--alex ignore dad-mom-->

A window will **not** pop up.
```

Yields:

```txt
readme.md: no issues found
```

Closes GH-16.

index.js

@@ -19,6 +19,7 @@
 var VFile = require('vfile');
 var remark = require('remark');
 var retext = require('retext');
+var control = require('remark-message-control');
 var english = require('retext-english');
 var equality = require('retext-equality');
 var remark2retext = require('remark-retext');
@@ -29,7 +30,10 @@ var sort = require('vfile-sort');
  */
 
 var text = retext().use(english).use(equality);
-var markdown = remark().use(remark2retext, text);
+var markdown = remark().use(remark2retext, text).use(control, {
+    'name': 'alex',
+    'source': 'retext-equality'
+});
 
 /**
  * Wrap the given processor.

package.json

@@ -41,9 +41,10 @@
     "get-stdin": "^5.0.0",
     "glob": "^6.0.1",
     "globby": "^4.0.0",
-    "remark": "^3.0.0",
     "meow": "^3.3.0",
     "minimatch": "^3.0.0",
+    "remark": "^3.0.0",
+    "remark-message-control": "^1.0.1",
     "remark-retext": "^1.1.0",
     "retext": "^1.0.0",
     "retext-english": "^1.0.0",

readme.md

@@ -55,6 +55,8 @@ $ npm install alex --global
 
 *   [.alexignore](#alexignore)
 
+*   [Ignoring messages](#ignoring-messages)
+
 *   [Workflow](#workflow)
 
 *   [FAQ](#faq)
@@ -219,6 +221,75 @@ components/
 example.md
 ```
 
+## Ignoring messages
+
+Sometimes, **alex** makes mistakes:
+
+```md
+A window will pop up.
+```
+
+Yields:
+
+```txt
+readme.md
+  1:15-1:18  warning  `pop` may be insensitive, use `parent` instead  dad-mom
+
+⚠ 1 warning
+```
+
+**alex** can silence message through HTML comments in markdown:
+
+```md
+<!--alex ignore dad-mom-->
+
+A window will **not** pop up.
+```
+
+Yields:
+
+```txt
+readme.md: no issues found
+```
+
+`ignore` turns off messages for the thing after the comment (in this
+case, the paragraph).
+It’s also possible to turn off messages after a comment by using
+`disable`, and, turn those messages back on using `enable`:
+
+```md
+<!--alex disable dad-mom-->
+
+A window will **not** pop up.
+
+A window will **not** pop up.
+
+<!--alex enable dad-mom-->
+
+A window will pop up.
+```
+
+Yields:
+
+```txt
+readme.md
+  9:15-9:18  warning  `pop` may be insensitive, use `parent` instead  dad-mom
+
+⚠ 1 warning
+```
+
+Multiple messages can be controlled in one go:
+
+```md
+<!--alex disable he-her his-hers dad-mom-->
+```
+
+...and all messages can be controlled by omitting all rule identifiers:
+
+```md
+<!--alex ignore-->
+```
+
 ## Workflow
 
 The recommended workflow is to add **alex** locally and to run it with your