Update Ubuntu version from 20.04 to 22.04 (#199)

* Update Ubuntu version from 20.04 to 22.04

* Add required sphinx theme

Author: ruivieira

.readthedocs.yaml

@@ -7,7 +7,7 @@ version: 2
 
 # Set the version of Python and other tools you might need
 build:
-  os: ubuntu-20.04
+  os: ubuntu-22.04
   apt_packages :
     - maven
   tools:
@@ -26,6 +26,7 @@ build:
 # install the package
 python:
   install:
+    - requirements: docs/requirements.txt
     - method: pip
       path: .
       extra_requirements:

docs/requirements.txt

@@ -0,0 +1 @@
+sphinx-rtd-theme