DOC: config: Rework and uniformize how TCP/HTTP rules are documented

DOC: config: Rework and uniformize how TCP/HTTP rules are documented

Now all these rules are documented using the same structure. First there is
a general description with the list of all supported actions. Then all
actions are described in details. Thus, it is easy to have a quick list of
all supported actions and this avoids to have a huge description with all
info about these actions. In addition, when it is possible, we make a
reference to already documented parts.