Small issues with new API docs

[TC-MO]

1. We are missing syntax highlighting for code examples
2. We have inconsistencies with table headers throughout docs, sometimes they are lowercase, sometimes capitalized|

3. Actors throughout prose & endpoint names is not capitalized

4.We have some comments left in the spec

5. Typo in Authentication section

6. Color of PUT requests between sidebar and main body is misaligned

[TC-MO]

#3 addressed in https://github.com/apify/apify-docs/pull/1331

[B4nan]

We are missing syntax highlighting for code examples

This is not 100% correct, we are missing just a few of the languages like C or Ruby. connected to the question of what we want to have in there. having more languages supported means a bigger CSS bundle. i would be in favor of removing some like R, Ruby or OCaml. I'll enable C, Java and a few more now

[B4nan]

4.We have some comments left in the spec

I believe this is on purpose, to let the writer know that the number needs to be in sync with some constant. The problem is that redoc treats this as HTML but the new plugin wont respect such comments. I am not sure if we want to get rid of them, we should rather find a way to make them not rendered (which should be most likely a markdown syntax comments, I'll test it out if it works with redoc too).

[B4nan]

Color of PUT requests between sidebar and main body is misaligned

This is resolved via #1344

[B4nan]

4.We have some comments left in the spec

This is resolved via #1371

Typo in Authentication section

This as well

[B4nan]

once #1371 is merged, only 2. and 3. are valid from this issue