doc: add bundle-format to TECH_DOCS

A link to the bundle-format was added in 5c8273d (bundle doc: rewrite
the "DESCRIPTION" section, 2021-07-31).

Ensure `technical/bundle-format.html` is created to avoid a broken link
in `git-bundle.html`.

Signed-off-by: Todd Zullinger <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: tmzullinger

Documentation/Makefile

@@ -90,6 +90,7 @@ SP_ARTICLES += $(API_DOCS)
 TECH_DOCS += MyFirstContribution
 TECH_DOCS += MyFirstObjectWalk
 TECH_DOCS += SubmittingPatches
+TECH_DOCS += technical/bundle-format
 TECH_DOCS += technical/hash-function-transition
 TECH_DOCS += technical/http-protocol
 TECH_DOCS += technical/index-format