Render author email addresses in markdown BIPs

[murchandamus]

@ajtowns pointed out in his BIP 3 review that the author email addresses in the preamble of BIPs in markdown format were not being rendered.

[murchandamus]

Alas, the formatting checker doesn’t accept this change.
It looks like we will need to adjust the formatting requirements so we can have the email addresses in the markdown file preamble rendered.

[ajtowns]

I'd suggest ajtowns@726df6f

[katesalazar]

ajtowns@726df6f dunno if it is more Markdown-idiomatic, but is more elegant for reading the raw document source.

[katesalazar]

From the Daring Fireball Introducing Markdown post

Markdown allows web writers to compose text using a simple, readable, plain text formatting syntax

(emphasis in "readable" is mine)

[murchandamus]

@ajtowns: Thanks, that looks great. I’ve used your commit instead of mine.

[murchandamus]

LGTM. I think it’s RFM. @jonatack?

[murchandamus]

This appears to be Perl for reading a file line by line, and requiring that the initial lines of the file either only contain the byte order mark, or ``` if it is a Markdown file or <pre> if it is a Mediawiki file.

[ajtowns]

It reads the next (first) line of the file, checks if the full line doesn't exactly match <pre> possibly preceded by the byte order marker, and aborts if it doesn't. Not sure why it's written as a while loop; it's not like it can actually enter the loop body twice.

[murchandamus]

In Perl, a while loop can be terminated by calling last, so this ends the while loop that is reading the preamble.

[jonatack]

Review ACK 726df6f

Thanks @ajtowns for spotting this and the patch.

Verified that all the BIPs in markdown format have been updated.

$ ls *.md  
CONTRIBUTING.md bip-0348.md     bip-0349.md     bip-0379.md