Add missing transcript links to episode data and pages

[samwisekind]

For example:

• http://web.archive.org/web/20110904112849/http://www.thesteamcast.com/episodes/47/episode47transcript.pdf
• http://web.archive.org/web/20110304154358/http://www.thesteamcast.com/episodes/48/episode48transcript.pdf

[samwisekind]

Episodes:

• Episode 19: https://docs.google.com/document/d/1uCBMD2tpM7oE-NTZCzKRToP31_PcF0uB_7c-bToh928/
• Episode 47: https://docs.google.com/document/d/1FEy86d9ONhHWGYvdtGqBvTwIgnhm_bfXG3pMfXgoBAg/
• Episode 48: https://docs.google.com/document/d/1sGCSc0ENe9b30v79Tp2RDrvhgsd3S8F5unDSjG4hRR4/

Snacks:

• Snack 1: https://docs.google.com/document/d/1xozqjWOMw-k-fnDSzCGrSP2Ko24yfUbHNQJ0zZrPgF8/