Support multiple OpenAI compatible providers (#34212)

TODO
- [x] OpenAI Compatible API Icon
- [x] Docs
- [x] Link to docs in OpenAI provider section about configuring OpenAI
API compatible providers

Closes #33992

Related to #30010

Release Notes:

- agent: Add support for adding multiple OpenAI API compatible providers

---------

Co-authored-by: MrSubidubi <dev@bahn.sh>
Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

crates/ui_input/src/ui_input.rs

@@ -97,6 +97,10 @@ impl SingleLineInput {
     pub fn editor(&self) -> &Entity<Editor> {
         &self.editor
     }
+
+    pub fn text(&self, cx: &App) -> String {
+        self.editor().read(cx).text(cx)
+    }
 }
 
 impl Render for SingleLineInput {