Update source/administration/production-notes.txt

update notes with NFS flags to let MongoDB work on a NFS drive.
DOCS-941 replication chaining
DOCS-941 review edits
DOCS-941 review edits II
avgObjSize is in bytes (not affected by scale)
DOCS-941 review edits III
Document initial random value for ObjectId counter

This was mentioned in the original spec, but missed being copied over to the new docs.
typo, small edits
DOCS-1116: correction about what's included in the maximum index length.
DOCS-1116 updating duplicated index limitations
DOCS-1024: clarifying language about locks in 2.2 in stats
someone accidentally a word
DOCS-992: including notes on js methods that don't return JSON
DOCS-985: creating new role for documentating new user roles
merge: typo/trivial phrasing improvements
merge: objectid counter random startpoint
merge: correction and clarification
DOCS-941 chained replication merge and edits
DOCS-941 additional edits
add sitemap index for root docs directory