Determine cut-off for read-only sites

[mattstratton]

Need to determine what the "cut off" is for sites to be migrated in a "read-only" state.

[mattstratton]

Duped in #97

[bridgetkromhout]

Is okay to have an issue for this! What I think we need to figure out: the date, and the process. The process might be messy - @mattstratton thinks sed & awk might be involved due to footers/headers.

[mattstratton]

See also #29 (existing issue) for discussion. Or we can close that issue and discuss it here.

[bridgetkromhout]

We determined the cut-off would be April 16th, per the timeline here: #96 (comment).