Previously, for a nested set of pairs in Markdown such as: ```markdown [foo "bar" b|az] [foo (bar) b|az] ``` Trying to do `mam` or similar would freeze. The generated parse tree for the former looks like this: ``` 0:0 - 1:0 inline 0:0 - 0:15 shortcut_link 0:0 - 0:1 "[" 0:1 - 0:14 link_text 0:5 - 0:6 """ 0:9 - 0:10 """ 0:14 - 0:15 "]" ``` The node surrounding the cursor is `link_text` and it has two children `"` but these are outside of the cursor, so we don't want to select them. This change makes it so we check that `pos_` is within the `open` and `close` node range so that we don't get stuck in a loop of finding the same `"` pair.