add support for svelte via svelteserver language server (#3644)

* add support for svelte via svelteserver language server
* svelte: fix Vint error and add a `svelteserver` simple test.

Co-authored-by: Joakim Repomaa <mail@j.repomaa.com>
Co-authored-by: Joakim Repomaa <mail@jreinert.com>

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

@@ -489,6 +489,9 @@ Notes:
   * `stylelint`
 * SugarSS
   * `stylelint`
+* Svelte
+  * `prettier`
+  * `svelteserver`
 * Swift
   * Apple `swift-format`
   * `sourcekit-lsp`

doc/ale-svelte.txt

@@ -0,0 +1,31 @@
+===============================================================================
+ALE Svelte Integration                                     *ale-svelte-options*
+
+
+===============================================================================
+prettier                                                  *ale-svelte-prettier*
+
+See |ale-javascript-prettier| for information about the available options.
+
+
+===============================================================================
+svelteserver                                          *ale-svelte-svelteserver*
+
+g:ale_svelte_svelteserver_executable     *g:ale_svelte_svelteserver_executable*
+                                         *b:ale_svelte_svelteserver_executable*
+  Type: |String|
+  Default: `'svelteserver'`
+
+  See |ale-integrations-local-executables|
+
+
+g:ale_svelte_svelteserver_use_global      *g:ale_svelte_svelteserver_use_global*
+                                          *b:ale_svelte_svelteserver_use_global*
+  Type: |Number|
+  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.txt

@@ -1438,6 +1438,7 @@ g:ale_linter_aliases                                     *g:ale_linter_aliases*
   \   'ps1': 'powershell',
   \   'rmarkdown': 'r',
   \   'rmd': 'r',
+  \   'svelte': ['svelte', 'javascript'],
   \   'systemverilog': 'verilog',
   \   'typescriptreact': ['typescript', 'tsx'],
   \   'verilog_systemverilog': ['verilog_systemverilog', 'verilog'],
@@ -1588,6 +1589,7 @@ g:ale_linters                                                   *g:ale_linters*
   \   'python': ['flake8', 'mypy', 'pylint', 'pyright'],
   \   'rust': ['cargo', 'rls'],
   \   'spec': [],
+  \   'svelte': ['eslint', 'svelteserver'],
   \   'text': [],
   \   'vue': ['eslint', 'vls'],
   \   'zsh': ['shell'],
@@ -3010,6 +3012,9 @@ documented in additional help files.
     stylelint.............................|ale-stylus-stylelint|
   sugarss.................................|ale-sugarss-options|
     stylelint.............................|ale-sugarss-stylelint|
+  svelte..................................|ale-svelte-options|
+    prettier..............................|ale-svelte-prettier|
+    svelteserver..........................|ale-svelte-svelteserver|
   swift...................................|ale-swift-options|
     sourcekitlsp..........................|ale-swift-sourcekitlsp|
   systemd.................................|ale-systemd-options|