Add SuperHTML linter for HTML (#5055)

ale_linters/html/superhtml.vim

@@ -0,0 +1,34 @@
+call ale#Set('html_superhtml_executable', 'superhtml')
+call ale#Set('html_superhtml_use_global', get(g:, 'ale_use_global_executables', 0))
+
+function! ale_linters#html#superhtml#GetCommand(buffer) abort
+    return '%e check --stdin'
+endfunction
+
+function! ale_linters#html#superhtml#Handle(buffer, lines) abort
+    let l:output = []
+    let l:pattern = '^\(.*\):\(\d\+\):\(\d\+\): \(.*\)$'
+
+    for l:line in a:lines
+        let l:match = matchlist(l:line, l:pattern)
+
+        if !empty(l:match)
+            call add(l:output, {
+            \ 'lnum': str2nr(l:match[2]),
+            \ 'col': str2nr(l:match[3]),
+            \ 'text': l:match[4],
+            \ 'type': 'E'
+            \})
+        endif
+    endfor
+
+    return l:output
+endfunction
+
+call ale#linter#Define('html', {
+\   'name': 'superhtml',
+\   'executable': {b -> ale#Var(b, 'html_superhtml_executable')},
+\   'command': function('ale_linters#html#superhtml#GetCommand'),
+\   'output_stream': 'stderr',
+\   'callback': 'ale_linters#html#superhtml#Handle',
+\})