Add CodeMash and QCon conference data

[Dewaldnel11]

Adds CodeMash and QCon to the conference dataset.

Claims:
/claim #10
/claim #11

Source notes:

• CodeMash: public CodeMash speaker benefits list states credentialed speakers receive a four-day pass and lodging/housing support, and PreCompiler primary speakers receive a $250 honorarium per 4-hour workshop: https://codemash.org/call-for-speakers-announcement/
• QCon: public QCon speaker information states QCon provides conference registration and covers hotel accommodation for non-local speakers; no public speaker-fee or SEA commitment was found, so this uses conservative values: https://qconnewyork.com/ny2012/qcon-nyc-2012/speakerinformation/index.html
• C4Media organizer reference: https://c4media.com/

Verification:

• git diff --check
• Markdown table column-count check for conference rows

[Dewaldnel11]

Withdrawing this PR and no longer pursuing the bounty/claim. Please disregard the earlier /claim lines.