Migrate idrac documentation to sysadm docs
The default credentials for dell and supermicro have been installed in the creds store.
Related to swh/infra/sysadm-environment#3154 (closed)
Test Plan
make -C sysadm html happy
and the build should be happy too now!
thanks to @anlambert \o/
Migrated from D6534 (view on Phabricator)