Add some notes on how to do the release

Just to not forget some steps

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Acked-by: Victor Toso <victortoso@redhat.com>

docs/how_to_release.md

@@ -0,0 +1,39 @@
+How to do a SPICE server release
+================================
+
+Some notes to prepare a release, not really strict but better to have in order
+to avoid forgetting something.
+
+* Update `configure.ac` and `meson.build` according to libtool rules
+* Update `CHANGELOG.md` with list of changes done since last release
+* Send a merge request with such changes, handle the review
+* Try to build an RPM package from `make dist` output (see below notes
+  on how to build a source tarball)
+* `git push` for the above MR
+* `git push` for the version tag created (for instance you can use
+  `git push origin v0.14.3` or `git push --tags`)
+* Send an email to spice-devel mailing list
+* Sign generated tarball (to create a detached signature run
+  `gpg2 -sb spice-release.tar.bz2`)
+* On Gitlab update tags (https://gitlab.freedesktop.org/spice/spice/-/tags)
+  * Add ChangeLog information
+  * Upload tarball and relative signature
+* Upload tarball and relative signature to
+  https://www.spice-space.org/download/releases/ (sftp to
+  `spice-uploader@spice-web.osci.io:/var/www/www.spice-space.org/`)
+* Update file `download.rst` in
+  https://gitlab.freedesktop.org/spice/spice-space-pages
+* Create a merge request for `spice-space-pages`
+
+How to build a source tarball
+-----------------------------
+
+1. `git tag -a v0.14.3 -m 'spice-server 0.14.3'` (replace the version)
+2. `git clone https://gitlab.freedesktop.org/spice/spice.git`
+3. `cd spice`
+4. `./autogen.sh --disable-dependency-tracking`
+5. `(cd subprojects/spice-common && make gitignore)`
+6. `make dist`
+
+Step 4 is to avoid a problem with `.deps` directories, step 5 to avoid
+the directory to be dirty due to missing `.gitignore` files.