[boot-time] New page for tracking boot-time activities

Hey kernel boot-time developers,

This month, I'm replacing our regular Boot-time SIG meeting (which normally
happens on the 4th Tuesday of every month), with a Birds-of-a-Feather (BoF)
session at Open Source Summit North America, as part of the Embedded
Linux Conference track.

Tthe BOF is Tuesday, June 24.
See here for session details: https://ossna2025.sched.com/event/1zfle?iframe=no

I've made a wiki page to keep track of some of the things that SIG participants
have mentioned that they have recently worked on, or are currently working on,
here:
https://elinux.org/Boot-Time_Activities

The page is not exhaustive.  I plan to review this page during the BoF.
If you have a project or work that you'd like to let others know about,
please email me, or add it to the page yourself.

Let's keep each other informed of the boot-time work we're doing!
 -- Tim