#1428 Start implementing LSP hover support

autoload/ale/lsp/message.vim

@@ -126,3 +126,12 @@ function! ale#lsp#message#References(buffer, line, column) abort
     \   'context': {'includeDeclaration': v:false},
     \}]
 endfunction
+
+function! ale#lsp#message#Hover(buffer, line, column) abort
+    return [0, 'textDocument/hover', {
+    \   'textDocument': {
+    \       'uri': ale#path#ToURI(expand('#' . a:buffer . ':p')),
+    \   },
+    \   'position': {'line': a:line - 1, 'character': a:column},
+    \}]
+endfunction