Add note to templates about alerting on call

Closes gitlab-org/release/tasks#165

See merge request !331

Fixes links packages.gitlab.com on release candidate template

See merge request !333

* Moving notification language to production section
* Canary and Staging deploy announcements should mention the on call

Improve QA section on issue's templates

See merge request !325

Improves step in "Packaging" section

See merge request !332

Also moves warm up step under 'Deployment' to both templates are
consistent

* In case another production engineer will be monitoring, alert the oncall that a
deploy is occuring.

Remove unnecessary packages.gitlab.com links from templates

Closes #192

See merge request !330

Remove unused `for_rc` argument for `Version#to_omnibus`

Closes #186

See merge request !328

Add `SharedStatus.security_release?`

See merge request !329

`SharedStatus.security_release?` is the SSOT for whether or not we're
performing a security release. It should not be able to be overridden by
method parameters.

Updates packages paths in patch release template

See merge request !327

No downtime is allowed, no tweets announcing deploy.

See merge request !326

Also add missing step to ensure the QA issue is announced on the respective slack channels

Include EE specific migrations in git diff command

See merge request !321

Adds notes in the MR preparation template for cherry picking & conflicts resolution

See merge request !320

do not require confirmation for staging/canary deploys in other templates

See merge request !324

# Conflicts:
#   templates/release_candidate.md.erb

do not require production notification on staging/canary

See merge request !323

* master:
  Links `Sync stable branches` point to documentation
  Fix parser removing a version

Links `Sync stable branches` point to documentation

See merge request !322

Fix parser removing a version

See merge request !319

Allow changelog entries to omit a type entirely, defaulting to "other"

Closes #191

See merge request !318