minor: fixing typo
DOCS-1522: reference material related to balancer control
Adds RHEL minimum version for ext4 FS support

Also fixes a regression of DOCS-1094

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-1208 agg command overview/xref

Signed-off-by: Sam Kleinman <samk@10gen.com>
minor: refactoring links and fixing a toc tree
theme: fixing jira collector problem
minor: fixing xref
fixing syntax of example
pulling text search covered query document
chainging version added tag for chaining allowed feature
Revert "pulling text search covered query document"

This reverts commit 5ddd5b9de134d0f1b8b1c3dcc2a1014c25a169fd.