Add explaination on prototype beta in docker version script

Author: bidoubiwa

.github/scripts/prototype-docker-version.sh

@@ -1,5 +1,15 @@
 #!/bin/sh
 
+# This script is ran whenever a PR is made to implement a Meilisearch prototype.
+# For example if Meilisearch creates a prototype for radioactive search, the SDK may implement a way to try out the radioactive search.
+# Nonetheless, the tests of this implentation should run against the prototype and not the latest release of Meilisearch.
+# To be able to do so, Meilisearch creates a docker image with the changes.
+# The purpose of this script is to find the correct docker image containing the changes.
+# For example,
+# The radioactive search docker image is named `v0.30.0-radioactive-search.beta.0`
+# our branch is named `prototype/radioactive-search.0`
+# Using the branch name, this script is going to retrieve the name of the docker image.
+
 # See https://docs.github.com/en/actions/learn-github-actions/environment-variables#default-environment-variables for references on GITHUB_REF_NAME
 prototype_branch=$1                                                        # $GITHUB_REF_NAME
 prototype_branch=$(echo $prototype_branch | sed -r 's/prototype-beta\///') # remove pre-prending prototype-beta/