Review the user manual to make sure it's consistent with 2.0

[joanise]

Just do a consistency check on https://roedoejet.github.io/g2p/latest/

[roedoejet]

The docs look OK to me, but the following blog posts need to be updated:

• https://blog.mothertongues.org/g2p-basic-mappings-local/
• https://blog.mothertongues.org/g2p-advanced-mappings/
• https://blog.mothertongues.org/g2p-case-feeding/

[joanise]

Results of my review so far:

• https://roedoejet.github.io/g2p/latest/studio/ has an outdated animated screen capture, and only mentions 4 of the 9 options we now support on https://g2p-studio.herokuapp.com/
• the screen capture for custom rules is missing the new Prevent Feeding column
• the custom abbreviations screen capture is in a different style than the current one, though it's not missing any features.

[joanise]

Plus #330

[joanise]

#332 and #333 together will complete the fixes to the manual.
There will just remain the fixes to the blog post.