Add a timeline for completion of mentorship.

[brooks]

Summary

This is intended to be a guideline and to set expecations for mentors and mentees. We've had a small number of cases where people got commit bits and then did little beyond their initial
commits. We'd like this situation to be clear. We expect future core teams will interpret with appropriate flexibility.

[imp]

en_US.ISO8859-1/articles/committers-guide/article.xml

2439

space after under here.

2442

s/complete/completion/ maybe?

[brooks]

• Fix issues reported by @imp.

[bcr]

Typo fix, the rest looks good.

en_US.ISO8859-1/articles/committers-guide/article.xml

2441

s/preverting/preventing/

[brooks]

• Typo fix, thanks @bcr.

[bcr]

Thanks, good to go!

[brooks]

• Another typo fix.

[jhb]

en_US.ISO8859-1/articles/committers-guide/article.xml

2443

Maybe s/should/will?

[brooks]

• Use "may" to indicate that transition to project member is at core's discretion.

[gnn]

I'm ok with "may" so LGTM.