Replace dashes with underscores

[ndporter]

Following best practices (see TidyData lesson column headers being created should use _ instead of - whenever possible. This applies at least to Looking up Data (e.g., Journal-details) but other episodes should be checked as well for consistency.

[ostephens]

Great suggestion @ndporter - thank you 🙏

If anyone is willing / able to check through the lesson and identify any other examples, or even better make the edits for the maintainers to then approve that would be amazing.

This tutorial shows how you can show us the exact line and make the edit for maintainers to approve

[ndporter]

I won't have a chance to do this in the near future, or I would have put in a PR myself. I will also note that images may need to be changed to be consistent with the text (including the example I identified).

[jas58]

I'll add a note to also make the hyphen in User-Agent an underscore.

And a question: Might this be an instructor note in addition to the text edits?

Also, what does the alt-text need to be? it is currently:
Add column by fetching URLs screen capture

Does the alt-text need to describe what the image looks like (but doesn't need to repeat preceding or following instructions):
"The preview panel should read Row 1's value is 1099-4300 and the third column shows the api.crossref address completed."

[bencomp]

I'll add a note to also make the hyphen in User-Agent an underscore.

If you meant the HTTP header: that should be a hyphen.

[ndporter]

Good catch @bencomp it's important to only change the column headers we create, not the data we're trying to pass through the API, whose structure is determined by the providers.

[ostephens]

Column names in "Looking up data" episode fixed by #310. Waiting on confirmation from @mahdi-robbani whether a review of all episodes was included in that work