Updated guitar lessons (#268)

* initial notes

* updated code samples

* splitting the page and preparing layout

* missing gamepad api

* added basic guitar activty md files

added initial draft of guitar lesson - in progress

* word smithing and adding detail for concepts listed

* word smithing and adding detail for concepts listed

* typo in file name

* missing macro

* replaced guitar.png with image from Julia Carlson

* adding a few pictures

* adding cards macros

* few tweaks

* image for accellerometer lesson xyz axis

* fixed the numbering buttons page
-fixed the numbering to restart for each section and asdded spaces after so they don't wrap

* adding a few video links

* pin-press - added circuit info

* more vids

* fixing latest commit

* edits to light sensor and pin-press

* updated descriptions, linking lesson

* pin-press and display-buttons updates
-added dode samples to pin press

* updated making video

* light-sensor updated numbering

* Clean up
Clean up of headings to template style, other fixes

* putting display in template
use h2 with "Step 1:" and image before text

* removed numbered lists for display & light
these topics are code complete

* more consistent formating
Acceleromenter, buttons, light sensosr

* Acceleration Lesson, added art
Lesson steps for Acceleration, art for degree F to C for Map anology+clean up of light sensor topic

* Pin Press code complete
some other basic fomats and edits

* Removed dashes in lesson names
renamed and fixed references to files with "-" in names

* rest of fles w/ dash in name changes

* fixed links to guitar activities

* updated acceleraomter section

* transparency 4 art, image text
added transarency and renamed art, added descriptive text for video and still images

* renamed art

* fixing the merge

* fixing hint

* moved step 2 outside ~hint block

* fixing snippets

* remove guitar from project list

* Duration/Materials consistent  format
moved out of ~avatar block

docs/projects/guitar/accelerometer.md

@@ -5,7 +5,6 @@
 ### ~avatar avatar
 
 Use the Accelerometer to control guitar tempo
-* Duration: 30 - 45 minutes
 * Concepts:
      * Gravity
      * Acceleration
@@ -18,6 +17,8 @@ Use the Accelerometer to control guitar tempo
 
 ### ~  
 
+## Duration: 30 - 45 minutes  
+  
 *accelerometer controlled tempo*  
 https://youtu.be/h_gPkBaVkoo
 TODO: add sound to video