minor: fix pdf generation
DOCS-4567: fix typo
aggregation navigation edits
adding additional information about the shell to the man page
clean up redundant information on landing page
clarifications on mongodump page
data model landing page reorganization
fix update field name
fix typo in table of contents description
tweaks to crud tutorial navigation page
normalize page structure for aggregation operatiors
Update intro-aggregation-boolean.rst

correct grammar

Signed-off-by: Sam Kleinman <samk@10gen.com>
clarify administration concepts nav page
shard key concepts
fixes to expire data tutorial
clarify mongodump --out option
clarifying page page description
DOCS-4571 2.8 covered queries and sharded collections
DOCS-4508 rel notes balancer info
2.8 update w: majority descriptions