Add yaml-language-server support for YAML (#2874) (#4029)

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

@@ -640,6 +640,7 @@ Notes:
   * `prettier`
   * `spectral`
   * `swaglint`
+  * `yaml-language-server`
   * `yamlfix`
   * `yamllint`
 * YANG

doc/ale-yaml.txt

@@ -105,6 +105,59 @@ g:ale_yaml_swaglint_use_global                 *g:ale_yaml_swaglint_use_global*
   See |ale-integrations-local-executables|
 
 
+===============================================================================
+yaml-language-server                                 *ale-yaml-language-server*
+
+Website: https://github.com/redhat-developer/yaml-language-server
+
+
+Installation
+-------------------------------------------------------------------------------
+
+Install yaml-language-server either globally or locally: >
+
+  npm install yaml-language-server -g  # global
+  npm install yaml-language-server     # local
+
+
+Options
+-------------------------------------------------------------------------------
+
+g:ale_yaml_ls_executable                             *g:ale_yaml_ls_executable*
+                                                     *b:ale_yaml_ls_executable*
+  Type: |String|
+  Default: `'yaml-language-server'`
+
+  This variable can be set to change the path to yaml-language-server.
+
+
+g:ale_yaml_ls_config                                     *g:ale_yaml_ls_config*
+                                                         *b:ale_yaml_ls_config*
+  Type: |Dictionary|
+  Default: `{}`
+
+  Dictionary containing configuration settings that will be passed to the
+  language server.  For example, to enable schema store: >
+      {
+    \   'yaml': {
+    \     'schemaStore': {
+    \         'enable': v:true,
+    \     },
+    \   },
+    \ }
+<
+  Consult the yaml-language-server documentation for more information about
+  settings.
+
+
+g:ale_yaml_ls_use_global                             *g:ale_yaml_ls_use_global*
+                                                     *b:ale_yaml_ls_use_global*
+  Type: |String|
+  Default: `get(g:, 'ale_use_global_executables', 0)`
+
+  See |ale-integrations-local-executables|
+
+
 ===============================================================================
 yamlfix                                                      *ale-yaml-yamlfix*
 

doc/ale.txt

@@ -3232,6 +3232,7 @@ documented in additional help files.
     prettier..............................|ale-yaml-prettier|
     spectral..............................|ale-yaml-spectral|
     swaglint..............................|ale-yaml-swaglint|
+    yaml-language-server..................|ale-yaml-language-server|
     yamlfix...............................|ale-yaml-yamlfix|
     yamllint..............................|ale-yaml-yamllint|
   yang....................................|ale-yang-options|