organize past meeting pages to display right side menu appropriately

[ghwood]

URL

Example: https://beta.ietf.org/how/meetings/past/99/

Expected Behavior

The last 10 meetings should be displayed in the right side bar.

The entire list of past meetings is available in the top item (title) of the right side bar).

Actual Behavior

(include a screen shot if you like)

Reproducing

• Browser:
• OS: [Operating System name] [Version]
• (anything else you think we might need to reproduce this)

[ghwood]

This is done!