Move linter documentation into separate files

doc/ale-php.txt

@@ -0,0 +1,31 @@
+===============================================================================
+ALE PHP Integration                                           *ale-php-options*
+
+
+-------------------------------------------------------------------------------
+phpcs                                                           *ale-php-phpcs*
+
+g:ale_php_phpcs_standard                             *g:ale_php_phpcs_standard*
+
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to specify the coding standard used by phpcs. If no
+  coding standard is specified, phpcs will default to checking against the
+  PEAR coding standard, or the standard you have set as the default.
+
+
+------------------------------------------------------------------------------
+phpmd                                                           *ale-php-phpmd*
+
+g:ale_php_phpmd_ruleset                           *g:ale_php_phpmd_ruleset*
+
+  Type: |String|
+  Default: `'cleancode,codesize,controversial,design,naming,unusedcode'`
+
+  This variable controls the ruleset used by phpmd. Default is to use all of
+  the available phpmd rulesets
+
+
+-------------------------------------------------------------------------------
+  vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl: