According to the output by `tmt --help`, the `tmt tests` is an official command
name.
```
$ tmt --version
tmt version: 1.38.0
$ tmt --help
...
Commands:
...
tests Manage tests (L1 metadata).
...
```
* Update the plan /plans/modified to run in CI. See the following link for the
condition `trigger == commit`.
https://tmt.readthedocs.io/en/stable/spec/context.html#trigger
* Add the plan /plans/all to run all the tests. The plan is not executed in CI
as a default. Don't trigger this plan in CI to save the infra resource and
the running time.
Note we don't describe the triggered environment such as local or CI in the
`summary` element in the plan /plans/all of the `plans.fmf`. Because this
plan is executed as a default, and users can override the triggered
environment by running the `tmt` with `trigger` option, such as
`tmt -c trigger=commit`. We don't want to give users the impression that the
plan only works in a specific running environment.
* Update the `README.md` removing the parts of the `plans --default` option in
the `tmt run` commands that are not needed due to the plan /plans/all.
Co-authored-by: Lukáš Zachar <lzachar@redhat.com>
* Add Contributing section including Testing sub section.
* Change the repository name's heading level.
Replace the heading level 2 syntax ("--") with the more popular heading level
1 syntax.
See <https://www.markdownguide.org/basic-syntax/> for details.
