Fix typo: arithmetric -> arithmetical
Merge pull request #40 from edx/sylvia/docs/math_formatting_typo

Fix typo: arithmetric -> arithmetical
Add weekly highlights template. Move Bulk Email to own section from Course Launch Activities
Merge pull request #38 from edx/carol/docs/DOC-1127

Carol/docs/doc 1127
Put December entries in new month in change log
RN 12/3/2014
Merge pull request #41 from edx/markhoeber-doc1254

First draft RN 12/3/2014
Add wiki info to student-facing documentation
Merge pull request #46 from edx/sylvia/docs/DOC-1132

Sylvia/docs/doc 1132
Reorg of cohorts and discussion topics
Excludes changes for always-cohort-inline-discussions (DOC-1077)
Merge pull request #48 from edx/carol/docs/DOC_cohorts

Reorg of cohorts and discussion topics
First draft
Edits per review comments