Issue on page /docs/d_crs_what_is_it.html

[rfpg]

Learning objective suggestions (I'd roll the first two into one):

1. Identify the properties of a Coordinate Reference System (CRS).
2. Differentiate between projected and geographic coordinate reference systems.
3. Identify the impact of a CRS on shape, area, and distance.

Other bits of feedback:

• I recommend that you update the title to "What is a Coordinate Reference System (CRS)?"
• Update figure numbering as needed (as per prior section updates).
• Expand the code snippet under Geographic Coordinate Systems as it's easy to miss and include some instructional text on what it actually does and why it matters.