PSScriptAnalyzer (#2370)

* Added psscriptanalyzer
* Added exclusions and documentation
* Added PSScriptAnalyzer handler test

doc/ale-powershell.txt

@@ -0,0 +1,62 @@
+===============================================================================
+ALE PowerShell Integration                             *ale-powershell-options*
+
+
+===============================================================================
+psscriptanalyzer                              *ale-powershell-psscriptanalyzer*
+
+Installation
+-------------------------------------------------------------------------------
+
+Install PSScriptAnalyzer by any means, so long as it can be automatically
+imported in PowerShell.
+Some PowerShell plugins set the filetype of files to `ps1`. To continue using
+these plugins, use the ale_linter_aliases global to alias `ps1` to `powershell`
+
+>
+  " Allow ps1 filetype to work with powershell linters
+  let g:ale_linter_aliases = {'ps1': 'powershell'}
+<
+
+g:ale_powershell_psscriptanalyzer_executable
+*g:ale_powershell_psscriptanalyzer_executable*
+                                 *b:ale_powershell_psscriptanalyzer_executable*
+  Type: |String|
+  Default: `'pwsh'`
+
+  This variable sets executable used for powershell.
+  
+  For example, on Windows you could set powershell to be Windows Powershell:
+>
+  let g:ale_powershell_psscriptanalyzer_executable = 'powershell.exe'
+<
+
+g:ale_powershell_psscriptanalyzer_module
+*g:ale_powershell_psscriptanalyzer_module*
+                                     *b:ale_powershell_psscriptanalyzer_module*
+  Type: |String
+  Default: `'psscriptanalyzer'`
+
+  This variable sets the name of the psscriptanalyzer module.
+  for psscriptanalyzer invocation.
+
+
+g:ale_powershell_psscriptanalyzer_exclusions 
+*g:ale_powershell_psscriptanalyzer_exclusions*
+                                 *b:ale_powershell_psscriptanalyzer_exclusions*
+  Type: |String|
+  Default: `''`
+
+  Set this variable to exclude test(s) for psscriptanalyzer
+  (-ExcludeRule option).  To exclude more than one option, separate them with
+  commas.
+
+>
+  " Suppress Write-Host and Global vars warnings
+  let g:ale_powershell_psscriptanalyzer_exclusions =
+  \  'PSAvoidUsingWriteHost,PSAvoidGlobalVars'
+<
+
+
+===============================================================================
+  vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:

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

@@ -315,6 +315,8 @@ Notes:
   * `write-good`
 * Pony
   * `ponyc`
+* PowerShell
+  * `psscriptanalyzer`
 * Prolog
   * `swipl`
 * proto

doc/ale.txt

@@ -275,6 +275,8 @@ ALE supports the following key features for linting:
       write-good..........................|ale-pod-write-good|
     pony..................................|ale-pony-options|
       ponyc...............................|ale-pony-ponyc|
+    powershell............................|ale-powershell-options|
+      psscriptanalyzer....................|ale-powershell-psscriptanalyzer|
     prolog................................|ale-prolog-options|
       swipl...............................|ale-prolog-swipl|
     proto.................................|ale-proto-options|