Extend README.md

Author: frafra

README.md

@@ -1,3 +1,26 @@
-# OpenRefine containers
+# How to build and run
 
-This repository hosts a collection of containerized packages of OpenRefine.
+```bash
+docker compose up --build
+```
+
+Configure by editing `docker-compose.yml`.
+
+# Upgrade
+
+Before building the new image, some operation could be needed.
+
+## Generate a template configuration file
+
+This is if the new version of OpenRefine has a different `refine.ini` configuration file.
+
+```bash
+version="3.7.5"
+curl -L "https://github.com/OpenRefine/OpenRefine/releases/download/${version}/openrefine-linux-${version}.tar.gz" |
+    tar xz --wildcards '*/refine.ini' --strip-components 1
+mv refine.ini refine.ini.template
+```
+
+The new `refine.ini.template` should still use the environmental variables as the previous one.
+This requires editing the file manually by comparing it to the old version.
+`git diff refine.ini.template` can be helpful.