docs: clarify steps to add custom lunr index code

[diablodale]

Follow-up doc updates from PR #1068
Merges several conversations from that PR and simplifies some language

Open to feedback 👍

[mattxwang]

Minor nit: can we keep the newline format of this file (i.e., not adding a newline when you hit ~ 80 characters)? It makes future git diffs not very helpful.

(down the line, I'll add some prettier automation to make this work)

I don't have any other major comments on the documentation right now, but I'll come back to it when I have more time (~ a day or so).

[diablodale]

Ill push update with single lines for everything. I'm not sure that's what you want so tell me when you see the commit.
FYI: all git tools can ignore whitespace with diffs; in github it is under the gear icon then choose ignore whitespace.

[mattxwang]

FYI: all git tools can ignore whitespace with diffs; in github it is under the gear icon then choose ignore whitespace.

Yup - I meant more, when we have another person commit and swap them back, etc. it introduces noise in the commit graph. Thanks for being so quick on this!

[mattxwang]

Gave it a more thorough look, this seems good to merge to me!

@diablodale any last comments before we merge? I'll try to not repeat my same mistake from last time.

[diablodale]

@diablodale any last comments before we merge? I'll try to not repeat my same mistake from last time.

LGTM