Show only the latest major versions in docs

When showing the docs switch menu it will show all the versions, and
there is a lot of them, since we don't need to show every minor version
there we do some shell magic to only keep the latest major versions in
the docs.

Here is what alltag variable was before

% for i in $(git tag -l|grep '^v'|sort -rn);do echo -n "$i,";done|sed 's/,$//'
v0.22.4,v0.22.3,v0.22.2,v0.22.1,v0.22.0,v0.21.5,v0.21.4,v0.21.3,v0.21.2,v0.21.1
,v0.21.0,v0.20.0,v0.19.6,v0.19.5,v0.19.4,v0.19.3,v0.19.2,v0.19.1,v0.19.0,
v0.18.0,v0.17.7,v0.17.6,v0.17.5,v0.17.4,v0.17.3,v0.17.2,v0.17.1,v0.17.0,
v0.16.0,v0.15.6,v0.15.5,v0.15.4,v0.15.3,v0.15.2,v0.15.1,v0.15.0,v0.14.3,
v0.14.2,v0.14.1,v0.14.0,v0.13.1,v0.13.0,v0.12.0,v0.11.1,v0.11.0%

and with this changes:

% bash /tmp/a.sh
v0.22.4,v0.21.5,v0.20.0,v0.19.6,v0.18.0,v0.17.7,v0.16.0,v0.15.6,v0.14.3,
v0.13.1,v0.12.0,v0.11.1

Signed-off-by: Chmouel Boudjnah <[email protected]>

.tekton/release-pipeline.yaml

@@ -72,7 +72,23 @@ spec:
                     exit
                 }
                 stable_tag=${version%.*}.x
-                alltags=$(for i in $(git tag -l|grep '^v'|sort -rn);do echo -n "$i,";done|sed 's/,$//')
+
+                # Keep all the latest major versions
+                # i.e: i have v0.5.1, v0.5.2, v0.6.1, v0.6.2, v0.7.1, v0.7.2
+                # it will keep v0.5.2, v0.6.2, v0.7.2
+                declare -A hashmap=()
+                for i in $(git tag -l | grep '^v' | sort -V); do
+                  version=${i//v/}
+                  if [[ ${version} =~ ^([0-9]+\.[0-9]+)\.[0-9]+$ ]]; then
+                    major_version=${BASH_REMATCH[1]}
+                  fi
+                  hashmap["$major_version"]=$version
+                done
+                output=$(for i in "${!hashmap[@]}"; do
+                  echo v"${hashmap[$i]}"
+                done | sort -rV | tr "\n" ", ")
+                alltags=${output%,}
+
                 allversions="nightly,stable,$alltags"
                 git config --global user.email "[email protected]"
                 git config --global user.name "Pipelines as Code CI Robot"