[doc] Add swift support documentation (#2426)

* [doc] Add swift support documentation
* [doc] Add swift bullets in main help file
* [doc] Add to supported languages and tools txt file as well
* Ensure same name styling for help/readme files

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

@@ -410,6 +410,7 @@ Notes:
 * SugarSS
   * `stylelint`
 * Swift
+  * `sourcekit-lsp`
   * `swiftformat`
   * `swiftlint`
 * Tcl

doc/ale-swift.txt

@@ -0,0 +1,21 @@
+===============================================================================
+ALE Swift Integration                                       *ale-swift-options*
+
+
+===============================================================================
+sourcekitlsp                                           *ale-swift-sourcekitlsp*
+
+To enable the SourceKit-LSP you need to install and build the executable as
+described here: https://github.com/apple/sourcekit-lsp#building-sourcekit-lsp
+
+
+g:ale_sourcekit_lsp_executable                 *g:ale_sourcekit_lsp_executable*
+                                               *b:ale_sourcekit_lsp_executable*
+  Type: |String|
+  Default: `'sourcekit-lsp'`
+
+  See |ale-integrations-local-executables|
+
+===============================================================================
+  vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:
+

doc/ale.txt

@@ -2151,6 +2151,8 @@ documented in additional help files.
     stylelint.............................|ale-stylus-stylelint|
   sugarss.................................|ale-sugarss-options|
     stylelint.............................|ale-sugarss-stylelint|
+  swift...................................|ale-swift-options|
+    sourcekitlsp..........................|ale-swift-sourcekitlsp|
   tcl.....................................|ale-tcl-options|
     nagelfar..............................|ale-tcl-nagelfar|
   terraform...............................|ale-terraform-options|

supported-tools.md

@@ -419,6 +419,7 @@ formatting.
 * SugarSS
   * [stylelint](https://github.com/stylelint/stylelint)
 * Swift
+  * [sourcekit-lsp](https://github.com/apple/sourcekit-lsp)
   * [swiftformat](https://github.com/nicklockwood/SwiftFormat)
   * [swiftlint](https://github.com/realm/SwiftLint)
 * Tcl