Convert filetypes to language IDs

internal/lsp/languages.go

@@ -0,0 +1,20 @@
+package lsp
+
+// mappings for when micro filetypes don't match LSP language identifiers
+var languages = map[string]string{
+	"batch":           "bat",
+	"c++":             "cpp",
+	"git-rebase-todo": "git-rebase",
+	"html4":           "html",
+	"html5":           "html",
+	"python2":         "python",
+	"shell":           "shellscript",
+	// "tex": "latex",
+}
+
+func Filetype(ft string) string {
+	if l, ok := languages[ft]; ok {
+		return l
+	}
+	return ft
+}