* Doc fixes and restructuring
This commit includes several misc changes to doc set. Create appendix
directory and add freq section with website images. Expand how-to
contribute section. Add reference to new 29 Host LAN mode. Add SNR sound
control to SNR graphs section. Add Radio Mobile Settings to How-To
section. Update images in Freq Spectrum section, and minimize reference
to "unshared" channels. Move Server Sync section to Services Overview.
* Fix misleading keyword search wording
Fix the misleading wording about doing a keyword search for AREDN.
* Fix total bandwidth allocation wording
Fix total bandwidth allocation wording in Radio Spectrum section.
* Clarify channel width at band edges
Clarify the warning against using wide channels that could transmit
outside of allowed FCC allocations.
* Heading change in services overview
* Add balancing comment about reducing channel width
Add a balancing comment that reducing channel width to increase SNR also
cuts throughput in half.
* Add SNR warning comment
* Fix reference to OpenWRT in screenshot
Replace reference to OpenWRT in screenshot with the AREDN login banner.
Steve Lewis KC0EUW