add spectral support for json

doc/ale-json.txt

@@ -101,5 +101,37 @@ prettier                                                    *ale-json-prettier*
 See |ale-javascript-prettier| for information about the available options.
 
 
+===============================================================================
+spectral                                                    *ale-json-spectral*
+
+Website: https://github.com/stoplightio/spectral
+
+Installation
+-------------------------------------------------------------------------------
+
+Install spectral either globally or locally: >
+
+  npm install @stoplight/spectral -g  # global
+  npm install @stoplight/spectral     # local
+<
+
+Options
+-------------------------------------------------------------------------------
+
+g:ale_json_spectral_executable                 *g:ale_json_spectral_executable*
+                                               *b:ale_json_spectral_executable*
+  Type: |String|
+  Default: `'spectral'`
+
+  This variable can be set to change the path to spectral.
+
+g:ale_json_spectral_use_global                 *g:ale_json_spectral_use_global*
+                                               *b:ale_json_spectral_use_global*
+  Type: |String|
+  Default: `get(g:, 'ale_use_global_executables', 0)`
+
+  See |ale-integrations-local-executables|
+
+
 ===============================================================================
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:

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

@@ -248,6 +248,7 @@ Notes:
   * `jq`
   * `jsonlint`
   * `prettier`
+  * `spectral`
 * Julia
   * `languageserver`
 * Kotlin

doc/ale.txt

@@ -2785,6 +2785,7 @@ documented in additional help files.
     jsonlint..............................|ale-json-jsonlint|
     jq....................................|ale-json-jq|
     prettier..............................|ale-json-prettier|
+    spectral..............................|ale-json-spectral|
   julia...................................|ale-julia-options|
     languageserver........................|ale-julia-languageserver|
   kotlin..................................|ale-kotlin-options|