[Canvas][Docs] Updates function reference

[cqliu1]

Summary

[skip-ci]

This updates the function reference using the content generated in #49402.

Changes:

• Fixes various typos
• Replaces open (“)/close (”) double quote with straight (") double quotes

Checklist

Use strikethroughs to remove checklist items you don't feel are applicable to this PR.

- [ ] This was checked for cross-browser compatibility, including a check against IE11

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
  - [ ] Unit or functional tests were updated or added to match the most common scenarios
  - [ ] This was checked for keyboard-only and screenreader accessibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately
• This includes a feature addition or change that requires a release note and was labeled appropriately

[elasticmachine]

Pinging @elastic/kibana-canvas (Team:Canvas)

[elasticmachine]

Pinging @elastic/kibana-docs (Team:Docs)

[KOTungseth]

Nice PR! I have some small suggestions, but otherwise LGTM.

[KOTungseth]

Is this supposed to be a question?

[cqliu1]

Yeah, some help descriptions of arguments that take a boolean value are written in the form of a question to indicate true as yes and false as no. Should we not do this?

[KOTungseth]

Same same

[KOTungseth]

Probably don't need to fix in this PR, or maybe at all, but my writer brain is flagging from which. I'm not sure if we care about using British English in our docs, but from which definitely fits in the British English realm.

[KOTungseth]

I'm thinking these are on purpose now... if so, please ignore all of my comments.

[KOTungseth]

When would I want to use a specialized function? Maybe add that information too?

[cqliu1]

We should probably go into detail in the expression language docs instead of in this help text. Basically if I have a datatable and I want to add a render as="plot" for instance at the end, it won't work without using the specialized plot function.