add ruby support for semantic search

crates/zed/src/languages/ruby/config.toml

@@ -10,3 +10,4 @@ brackets = [
   { start = "\"", end = "\"", close = true, newline = false, not_in = ["comment", "string"] },
   { start = "'", end = "'", close = true, newline = false, not_in = ["comment", "string"] },
 ]
+collapsed_placeholder = "# ..."

crates/zed/src/languages/ruby/embedding.scm

@@ -0,0 +1,22 @@
+(
+    (comment)* @context
+    .
+    [
+        (module
+            "module" @name
+            name: (_) @name)
+        (method
+            "def" @name
+            name: (_) @name
+            body: (body_statement) @collapse)
+        (class
+            "class" @name
+            name: (_) @name)
+        (singleton_method
+            "def" @name
+            object: (_) @name
+            "." @name
+            name: (_) @name
+            body: (body_statement) @collapse)
+        ] @item
+    )