some improvements for jsg/README.md

[seeekr]

trafficstars

WIP, still reading/working my way through the file, but wanted to open PR already anyway :)

Thanks for open-sourcing this, amazing to finally be able to check it out! And great work on the product itself, of course! :)

[kentonv]

Thanks! Assigning this to @jasnell (who is currently out for a couple days) as he wrote this file.

[seeekr]

Done with the file! Added a 2nd commit that contains some "review comments" that I'd be happy to turn into concrete changesets, if desired!

[jasnell]

Thank you @seeekr ! I'll be able to take a look tomorrow and will post some feedback then

[seeekr]

@jasnell Did you get around to taking a look yet? :-) I can also offer to split off the stuff/comments that might necessitate some more thinking & potentially discussion into another PR or so, so it's more straightforward to just accept the uncontroversial changes?

LMK!

[jasnell]

Not yet! Been pretty tied up the last two weeks.

[seeekr]

Thanks a lot for the review! I'll work through your comments and add some additional changes!

[Warfields]

Ping @seeekr