Add a keyword to active toolbox just like notion

[aquarius-wing]

How to get this effect: Press the / button in any block, and then show the toolbox, when I choose one item in list,the editorjs will insert block after current block.Just like notion.
This is my idea:

1. Go to blockManager.ts file, check the function blockDidMutated
2. Check the block.holder.innertText is endWith "/" and mutationType is BlockMutationType.Changed
3. Then, I open the toolbox, and there is the question
4. How to cut the "/" text from the block?