T controller tutorial and improve documentation

add tutorial for Berlin hands-on workshop

+ improve the documentation (hints for structure welcome)
+ remove 'optional' parameter property
  (is not yet used - should not appear in doc)
+ added test property in frappy_demo.cryo alters Parameter class
  ('test' property appears in Parameter doc)

Change-Id: I3ea08f955a92f72451fd23a5ff00d1185c7fb00e

doc/source/conf.py

@@ -58,7 +58,7 @@ master_doc = 'index'
 
 # General information about the project.
 project = 'Frappy'
-copyright = '2017-2021, Enrico Faulhaber, Markus Zolliker,'
+copyright = '2017-2023, Enrico Faulhaber, Markus Zolliker,'
 #copyright = '2017, SECoP Committee'
 author = 'Enrico Faulhaber, Markus Zolliker'
 
@@ -211,7 +211,7 @@ epub_exclude_files = ['search.html']
 
 
 # Example configuration for intersphinx: refer to the Python standard library.
-intersphinx_mapping = {'https://docs.python.org/3/': None}
+# intersphinx_mapping = {'https://docs.python.org/3/': None}
 
 from frappy.lib.classdoc import class_doc_handler