add yaml actionlint support (github actions) (#4173)

Co-authored-by: bretello <bretello@distruzione.org>

doc/ale-supported-languages-and-tools.txt

@@ -648,6 +648,7 @@ Notes:
 * XML
   * `xmllint`
 * YAML
+  * `actionlint`
   * `circleci`!!
   * `prettier`
   * `spectral`

doc/ale-yaml.txt

@@ -2,6 +2,28 @@
 ALE YAML Integration                                         *ale-yaml-options*
 
 
+===============================================================================
+actionlint                                                *ale-yaml-actionlint*
+
+Website: https://github.com/rhysd/actionlint
+
+
+Installation
+-------------------------------------------------------------------------------
+
+See installation guide: https://github.com/rhysd/actionlint#quick-start
+
+Options
+-------------------------------------------------------------------------------
+
+g:ale_yaml_actionlint_executable             *g:ale_yaml_actionlint_executable*
+                                             *b:ale_yaml_actionlint_executable*
+  Type: |String|
+  Default: `'actionlint'`
+
+  This variable can be set to change the path to actionlint.
+
+
 ===============================================================================
 circleci                                                    *ale-yaml-circleci*
 

doc/ale.txt

@@ -3272,6 +3272,7 @@ documented in additional help files.
   xml.....................................|ale-xml-options|
     xmllint...............................|ale-xml-xmllint|
   yaml....................................|ale-yaml-options|
+    actionlint............................|ale-yaml-actionlint|
     circleci..............................|ale-yaml-circleci|
     prettier..............................|ale-yaml-prettier|
     spectral..............................|ale-yaml-spectral|