Update readme.

Author: joedolson

README.md

@@ -13,6 +13,21 @@ To install:
 
 With plug-ins that have premium extensions, such as WP Tweets PRO for WP to Twitter, some extensions only work when the premium add-on is also installed. 
 
-These aren't full-scale plug-ins; these are examples for how to use the filters and actions in my plug-ins to extend or customize their functionality. Most examples require editing the code to change how they operate, and don't add any admin options.
+# What makes it a plugin?
+
+The header block is a section of comments that describe the plugin, and are used to identify that this is a plugin. A header block will look something like this:
+
+```/*
+Plugin Name: Name of my Custom Plugin
+Plugin URI: http://www.joedolson.com
+Description: Describe what this plug-in does
+Author: Joe Dolson
+Version: 1.0.0
+Author URI: http://www.joedolson.com/
+*/```
+
+Any PHP file in the `/wp-content/` directory that has this comment will be recognized as a plug-in.
+
+The plug-ins in this repository are simple examples. They don't have options or settings, they are examples for manipulating the filters and actions in my plugins to customize their functionality. In most cases, you'll need to edit the code to change how they operate.
 
 Thanks!

my-calendar/my-calendar-custom-fields.php

@@ -97,4 +97,3 @@ function my_event_email_tag( $details, $event ) {
 
 	return $details;
 }
-

wp-to-twitter/replace-space-character-in-tags.php

@@ -8,7 +8,6 @@
  * Author URI: http://www.joedolson.com
  */
 
- 
 add_filter( 'option_jd_replace_character', 'replace_spaces' );
 /*
  * Replace default character (usually blank) with an underscore.