Update sidebar links

[ymdahi]

Remove:

• LibreMaps
• ImathAS
• WebWork
• Query Library

Rename:

• get page contents -> get page source

Fix:

• Get Text Cover
• Generate Front/back

[ymdahi]

Get Cover Text:

calls cover(), which is not defined.

Generate Front/Back:

calls batch(), which is not defined.

[Miniland1333]

Has this already been fixed by ba57ba5?