Create laserscanner.rst

First draft of LaserScan rep.
Add units to time_offset
Change intensity parameter to more descriptive "publish_intensity"
Change *_angle params to angle_* to match messages
Merge pull request #1 from ericperko/laserscanner

Laserscanner
Updated to add more description to topics/params
Using assigned number REP 138
Posted to ros-users on 2/25
Updated topic section to contain new headers for required and support topics
Changed intense to most_intense for topic name
Updated parameter descriptions
Merge branch 'laserscanner' of github.com:chadrockey/rep into laserscanner
Incorrect lowercase on letter 's'
Forgot to change REP number inside text.
Incorporating kwc's suggestions.
Small grammar fix.
Added parameter 'publish_multiecho'
Made Active, added discussion references.
Merge pull request #25 from chadrockey/laserscanner

REP 138 LaserScan Common Topics, Parameters, and Diagnostic Keys Merging as Active