RELEASE_NOTES: Properly encapsulate symbols in backticks
RELEASE_NOTES: Properly encapsulate symbols in backticks

This allows the output to look nicer, and makes markdown less
confused when it finds an `_`.

Change-Id: Ib335728a2d256826a45e2e2fa3174e0a004e9fab
Reviewed-on: http://review.couchbase.org/39278
Tested-by: Mark Nunberg <e7d42768707bf23038325b0b68d4b577e5f6064a@haskalah.org>
Reviewed-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>

couchbase/libcouchbase,signmotion/libcouchbase,mody/libcouchbase,kojiromike/libcouchbase,avsej/libcouchbase,senthilkumaranb/libcouchbase,signmotion/libcouchbase,mody/libcouchbase,maxim-ky/libcouchbase,couchbase/libcouchbase,mnunberg/libcouchbase,avsej/libcouchbase,PureSwift/libcouchbase,mnunberg/libcouchbase,senthilkumaranb/libcouchbase,couchbase/libcouchbase,mnunberg/libcouchbase,kojiromike/libcouchbase,mody/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,mnunberg/libcouchbase,avsej/libcouchbase,PureSwift/libcouchbase,avsej/libcouchbase,maxim-ky/libcouchbase,kojiromike/libcouchbase,mnunberg/libcouchbase,couchbase/libcouchbase,senthilkumaranb/libcouchbase,maxim-ky/libcouchbase,senthilkumaranb/libcouchbase,couchbase/libcouchbase,maxim-ky/libcouchbase,signmotion/libcouchbase,PureSwift/libcouchbase,avsej/libcouchbase,signmotion/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,mody/libcouchbase,PureSwift/libcouchbase