Edit ruleset page

[asdine]

Create a page that allows editing the latest ruleset version in order to create a new one

Path: GET /rulesets/<path>/edit
Get data from: GET /i/rulesets/<path>
Submit data to: PATCH /i/rulesets/<path>

Sketch:

Related to #36

[yaziine]

I will postpone this and begin by the latest ruleset page (#32) which is needed to be able to access to the edit page.