add docker-compose.yml, refactor for docker volume usage

user defined data should not be mixed with static application data in
one directory.

therefore we need to move some files like db and userconfig to separate
directories, which can then be declared as docker volumes.

README.md

@@ -18,4 +18,36 @@ Because nobody should have to deal with a homemade spreadsheet or a shoebox full
 - Bootstrap-DatePicker
 - SweetAlert2
 - CsvHelper
-- Chart.js
+- Chart.js
+
+## Docker
+
+### manual
+
+- build
+
+```
+docker build -t hargata/lubelog:latest .
+```
+
+- run
+
+```
+docker run -d hargata/lubelog:latest
+```
+
+add `-v` for persistent volumes as needed. Have a look at the docker-compose.yml for examples.
+
+## docker-compose
+
+- build image
+
+```
+docker compose build
+```
+
+- run
+
+```
+docker compose build
+```