Update template docs

[liferoad]

Fixes #1907

Ran to update all the template docs:

mvn clean prepare-package \
  -DskipTests \
  -PtemplatesSpec

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 45.08%. Comparing base (f09e241) to head (6ed5c54).
Report is 2 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1966      +/-   ##
============================================
- Coverage     45.09%   45.08%   -0.02%     
- Complexity     3611     3934     +323     
============================================
  Files           835      835              
  Lines         49708    49708              
  Branches       5234     5234              
============================================
- Hits          22417    22412       -5     
- Misses        25625    25629       +4     
- Partials       1666     1667       +1     

Components	Coverage Δ
spanner-templates	66.25% <ø> (-0.02%)	⬇️
spanner-import-export	64.16% <ø> (-0.05%)	⬇️
spanner-live-forward-migration	76.18% <ø> (ø)
spanner-live-reverse-replication	76.54% <ø> (ø)
spanner-bulk-migration	85.57% <ø> (ø)

Files with missing lines	Coverage Δ
...ogle/cloud/teleport/templates/PubSubToDatadog.java	22.40% <ø> (ø)

... and 2 files with indirect coverage changes

[Polber]

Thanks

[damondouglas]

@liferoad LGTM

[liferoad]

I am going to merge this now.