Update README

Author: sirbrillig

README.mkdn

@@ -1,31 +1,40 @@
-PHP_CodeSniffer VariableAnalysis
-================================
+# PHP_CodeSniffer VariableAnalysis
 
-Plugin for PHP_CodeSniffer static analysis tool that adds analysis of problematic
-variable use.
+Plugin for PHP_CodeSniffer static analysis tool that adds analysis of problematic variable use.
 
  * Performs static analysis of variable use.
  * Warns on use of undefined variables.
  * Warns if variables are set or declared but never used within that scope.
  * Warns if variables are redeclared within same scope.
  * Warns if $this, self::$static_member, static::$static_member is used outside class scope.
 
-INSTALLATION
-------------
+## Installation
 
-Run ./install.sh -h to get install help.
+### Requirements
 
-For a default install of PHP_Codesniffer via PEAR with PEAR in ~/pear you should be
-safe to just run ./install.sh to use the default options, then copy the rules from
-ruleset.xml into your own ruleset.xml.
+VariableAnalysis requires PHP 5.4 or higher and [PHP CodeSniffer](https://github.com/squizlabs/PHP_CodeSniffer) version **3.0.2** or higher.
 
-CUSTOMIZATION
--------------
+### Standalone
+
+1. Install PHP_CodeSniffer by following its [installation instructions](https://github.com/squizlabs/PHP_CodeSniffer#installation) (via Composer, Phar file, PEAR, or Git checkout).
+
+   Do ensure that PHP_CodeSniffer's version matches our [requirements](#requirements)
+
+2. Clone the repository:
+
+        git clone -b master https://github.com/sirbrillig/VariableAnalysis.git VariableAnalysis
+
+3. Add its path to the PHP_CodeSniffer configuration:
+
+        phpcs --config-set installed_paths /path/to/VariableAnalysis
+
+If you already have installed paths, [use a comma to separate them](https://github.com/squizlabs/PHP_CodeSniffer/wiki/Configuration-Options#setting-the-installed-standard-paths).
+
+## Customization
 
 There's a variety of options to customize the behaviour of VariableAnalysis, take
 a look at the included ruleset.xml for commented examples of a configuration.
 
-KNOWN ISSUES & BUGS
--------------------
+## Original
 
- * File scope isn't currently analysed.
+This was forked from the excellent work in https://github.com/illusori/PHP_Codesniffer-VariableAnalysis