[ci] Fix path to update-site zip (part 2)

- Also update documentation
- remove old build scripts

Refs #271

Author: adangel

.ci/README.md

@@ -5,7 +5,7 @@
 Since 7.9.0, the plugin is signed with the same GPG key, that is used to sign the main PMD artifacts
 for maven central.
 
-See <https://github.com/pmd/build-tools/blob/main/scripts/files/release-signing-key-2EFA55D0785C31F956F2F87EA0B5CA1A4E086838-public.asc>.
+See <https://docs.pmd-code.org/latest/pmd_userdocs_signed_releases.html>.
 
 Tycho's [GPG Plugin](https://tycho.eclipseprojects.io/doc/latest/tycho-gpg-plugin/sign-p2-artifacts-mojo.html)
 is used for that.
@@ -14,8 +14,8 @@ There is no need anymore to use jar signer and use a real Let's Encrypt certific
 
 **How it works:**
 
-* During build setup, the private gpg key is imported from the environment variable `PMD_CI_GPG_PRIVATE_KEY`
-  which is a secret in GitHub Action. This environment variable is used by `pmd_ci_setup_secrets_private_env`
-  which is called by `build.sh` (but not for pull requests).
+* The GPG key is only needed for the two workflows `publish-snapshot.yml` and `publish-releases.yml`
+* The key is setup with setup-java, the private gpg key is imported from the (secret) environment
+  variable `PMD_CI_GPG_PRIVATE_KEY`.
 * The gpg plugin uses the environment variable `MAVEN_GPG_PASSPHRASE` for the passphrase. This is
   configured as well as a secret. The tycho gpg plugin is activated only when profile `sign` is activated.

.ci/build.sh

@@ -155,7 +155,7 @@ jobs:
         run: |
           uploadUrl="${PMD_SF_USER}@web.sourceforge.net:/home/frs/project/pmd/pmd-eclipse/zipped/"
           rsync -avh \
-              "net.sourceforge.pmd.eclipse.p2updatesite-*.zip" \
+              net.sourceforge.pmd.eclipse.p2updatesite-*.zip \
               "${uploadUrl}/net.sourceforge.pmd.eclipse.p2updatesite-SNAPSHOT.zip"
 
       - name: Cleanup ssh
@@ -206,7 +206,7 @@ jobs:
           qualifiedVersion="${qualifiedVersion#net.sourceforge.pmd.eclipse.p2updatesite-}"
 
           rm -rf snapshot
-          unzip -q -d snapshot "../net.sourceforge.pmd.eclipse.p2updatesite-*.zip"
+          unzip -q -d snapshot ../net.sourceforge.pmd.eclipse.p2updatesite-*.zip
           echo "This is a Eclipse Update Site for the [PMD Eclipse Plugin](https://github.com/pmd/pmd-eclipse-plugin/) ${VERSION}.
 
           Use <https://pmd.github.io/pmd-eclipse-plugin-p2-site/snapshot/> to install the plugin with the Eclipse Update Manager.