feat: replace Monaco by Ace

- Remove the Monaco Editor because it was to heavy and hard to integrate
- Use Ace instead
- Use the lowercase identifier for languages (ex: "Text" -> "text")
- Select automatically the default language in the drop down to create a note
  (like the expiration)
- Add `ace_directory` to serve assets from a local folder instead of a CDN
- "hcl" syntax highlighting has been removed
- "go" syntax highlighting has been renamed to "golang"
- Add option to disable the editor

Fixes #32.

Signed-off-by: Julien Riou <julien@riou.xyz>

src/server/handlers_web.go

@@ -23,6 +23,7 @@ type PageData struct {
 	Expirations              []int
 	Expiration               int
 	Languages                []string
+	Language                 string
 	Err                      error
 	URL                      string
 	Note                     *Note
@@ -30,7 +31,9 @@ type PageData struct {
 	EnableUploadFileButton   bool
 	AllowClientEncryptionKey bool
 	AllowNoEncryption        bool
+	AceDirectory             string
 	BootstrapDirectory       string
+	DisableEditor            bool
 }
 
 type HomeHandler struct {