Cleanup to episode 11

[ErinBecker]

This PR continues cleanup to episode 11 as discussed in #165.

The following changes are included.

Episode 11

• Needs to be ggplotized. Discussed in convert static plotting from base r to ggplot2 #133 Partially addressed in Clean-up to episode 10 and 11 #217
• Move comments to narrative for stylistic consistency.
• Remove line starting "If you completed .csv to Shapefile in R you have these plot"
• Move bullet point extra resources to callout (multiple places)
• Broken image link at start of "Extract Raster Pixels Values Using Vector Polygons"
• Sentence fragment - meant to be a section header? "Extract raster information using a polygon boundary."
• "In this case," used twice in adjoining sentences.
• data.frame and list should be plain text.
• Broken header "##Extract Data using x,y Locations"
• Broken image link in ##Extract Data using x,y Locations section

[ErinBecker]

Review appreciated from @datacarpentry/geospatial-maintainers

[obrl-soil]

if you add fill = NA to the first call - geom_sf(data = aoi_boundary_HARV, color = "blue") + you can then move the call so it draws after/over the raster. That way the outline doesn't get cut off

[ErinBecker]

Great, thanks! I was trying to figure out how to do this and having a heckofa time.

[obrl-soil]

Looks good!

[obrl-soil]

Is this a good place to also talk about cellStats()? It can be used to get fast summaries for whole rasters - mean, median, sd etc like cellStats(CHM_HARV, mean, na.rm = TRUE)

[ErinBecker]

Thanks @obrl-soil for the review and merge. I added a link to your comments to #165 so I don't forget to address them.