zephyr: tests: Add doc with fix-it week resources
zephyr: tests: Add doc with fix-it week resources

A central place to link material for fix-it week participants.

BUG=None
BRANCH=None
TEST=None

Signed-off-by: Tristan Honscheid <1e17951ff5ffc8afe254954c03de64afef62fe52@google.com>
Change-Id: Icb7ecf9772067da0da6bb36d86b1184c3449a614
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3824960
Reviewed-by: Yuval Peress <50dc11c009bd4d7e9d9d15a383c1743ce5ee82ef@google.com>
Tested-by: Yuval Peress <50dc11c009bd4d7e9d9d15a383c1743ce5ee82ef@google.com>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec