Update gps.h

Add hdop information in order to display GPS quality signal in telemetry
Update gps.c

Compute GPS quality signal
Embedded Crius CO-16 Modification Images
Added Gimli-Based docs/*.md -> PDF Generation
Manual-Generation (*.md -> pdf) via Gimli
Replaced diagram image with a scaled down png
dedicated folder for developer docs
dedicated folder for developer docs
using a fixed order of md files for pdf conversion
do not include generated pdf in the repo
fixed formatting
added manual building guide
fixed formatting
Merge branch 'pulsar256-master'
Merge pull request #93 from airmamaf/patch-2

Add Horizontal Dilution Of Precision to telemetry (1/2)
Merge pull request #92 from airmamaf/patch-1

Add Horizontal Dilution Of Precision to telemetry (2/2)
Minor documentation amends

Post proofing amends
Fix led cli command when led strip feature is not enabled.  Fixes #95.
Fix unable to disable GPS HOME mode.  Fixes #91.
Update warning mode leds to show when arming is disabled.

Idea and initial implementation by viktor80.  Closes #96.