Add ad-hoc FRU section to the tlbmc onboarding guide.

PiperOrigin-RevId: 745354806
Change-Id: I30de2e57cbacadcd1e652d07784aa1059faa66f4

gbmcweb

diff --git a/gbmcweb b/gbmcweb
index 736bfb4..1f60b98 160000
--- a/gbmcweb
+++ b/gbmcweb
@@ -1 +1 @@
-Subproject commit 736bfb47b92ab46dac74b5a18b448b0f139f2a85
+Subproject commit 1f60b9866faef1afac7e1f16f14f9db11ff0fd64