Move linter documentation into separate files

doc/ale-css.txt

@@ -0,0 +1,38 @@
+===============================================================================
+ALE CSS Integration                                           *ale-css-options*
+
+
+-------------------------------------------------------------------------------
+stylelint                                                   *ale-css-stylelint*
+
+g:ale_css_stylelint_executable                 *g:ale_css_stylelint_executable*
+
+  Type: |String|
+  Default: `'stylelint'`
+
+  ALE will first discover the stylelint path in an ancestor node_modules
+  directory. If no such path exists, this variable will be used instead.
+
+  If you wish to use only a globally installed version of stylelint, set
+  |g:ale_css_stylelint_use_global| to `1`.
+
+g:ale_css_stylelint_options                    *g:ale_css_stylelint_options*
+
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to pass additional options to stylelint.
+
+g:ale_css_stylelint_use_global                 *g:ale_css_stylelint_use_global*
+
+  Type: |String|
+  Default: `0`
+
+  This variable controls whether or not ALE will search for a local path for
+  stylelint first. If this variable is set to `1`, then ALE will always use the
+  global version of stylelint, in preference to locally installed versions of
+  stylelint in node_modules.
+
+
+-------------------------------------------------------------------------------
+  vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl: