rename `course_feature_type` to `learningResourceType`

As a OCW admin, I'd like to have our metadata fields align, where possible, with widely used metadata schemes.

To this end, we can rename course_feature_tags to match schema.org/LMRI's learningResourceType.

replace

ocw-hugo-projects/ocw-course/ocw-studio.yaml

Lines 200 to 201 in 9a10fdc

    
           - label: "Course Feature Tags" 
        
             name: "course_feature_tags"

with:

          - label: "Learning Resource Type"
            name: "learningResourceType"

related issues

- Since this is schema.org markup, it should be expressed in course hugo theme to maximize SEO

Question: is it necessary or desirable to match the camel-case used in schema.org? Or should we retain our underscore-separated naming?

@pdpinch Since the name property ultimately ends up being the key in the data template, I'd prefer if we could use underscores to keep everything consistent. Personally, I find underscore separated naming easier to read and prefer it to camel case but that's just my opinion. Either way, I think we should stay consistent here.

Ok, as long as you don't think it's too confusing to (eventually) have a hugo theme that maps course metadata learning_restource_type to learningResourceType in JSON-LD.

In my mind, underscore separated is better for JSON / YAML keys and Python variables / constants but in Javascript camel case is better for variables and constants. I could just be subtlety influenced by our formatting rules though...