Before pseudo-selector should not be clickable when showing branch lines

[bobbyg603]

Other information:

If you follow this documentation to introduce branch lines the before pseudo selector is clickable even though it's outside of the wrapper.

Here's a Stack Blitz that demonstrates this.

Also, here's a video from our app where we noticed this issue:

angular-tree-component-720p.mov

I would be willing to submit a PR for the docs ❤️

[x] Yes (Assistance will be provided if you need help to submit a pull request)
[ ] No

[bobbyg603]

@tobiasengelhardt i noticed you contributed to the library recently. can you please get me in touch with someone who might point me in the right direction for submitting a fix?