feat(starlark): add function, loop, and conditional textobjects

Author: PeterCardenas

queries/starlark/textobjects.scm

@@ -0,0 +1,18 @@
+(function_definition
+  body: (block)? @function.inner) @function.outer
+
+(while_statement
+  body: (block)? @loop.inner) @loop.outer
+
+(for_statement
+  body: (block)? @loop.inner) @loop.outer
+
+(if_statement
+  alternative: (_
+    (_) @conditional.inner)?) @conditional.outer
+
+(if_statement
+  consequence: (block)? @conditional.inner)
+
+(if_statement
+  condition: (_) @conditional.inner)