Aliasing headfirst → head_first
Link to alias

Reason:

Unrelated:

• lemons -> lemon
• musical_notes -> musical_note

Approved all.

Note: I know there are some characters named "Lemon" (either in full name or as a nickname) but those should really be tagged with lemon_(character) or their own individual character tag. Same with the artists who sometimes go by "Lemon" as a short version of their name, they are much better tagged as "lemon_(artist) or as their full artist username if at all possible. The just lemon tag needs to stay a general tag just for the citrus fruit itself. So even though that may come up occasionally, that is why this was still approved.