"Cooking mode" - specific display of recipe

Problem
When cooking a recipe from the Cookbook most users will probably have the browser open and scroll through the recipe. From time to time the display on mobile devices might turn off which is in itself annoying and with dirty hands even more so.

Possible Solution
Add a button in the recipe view to enter a specific mode of displaying the recipe which might have the following features (tbd):

• instructions are shown in full-screen mode
• cooking steps are shown one-by-one (depending on screen size, the next step by also be shown in a muted color)
• larger font, so you can read it even when the device is standing further away
• Next and Previous buttons for navigating through the recipe
• X button for leaving "Cooking mode"
• Ingredients button for having a quick look at the ingredients, since they may be referenced in an instruction
• The last shown instruction should be remembered, so that the recipe can be continued when re-entering the "Cooking mode"
• the display is kept active

Start by reviewing the recipe view referenced in the issue and compare the proposed cooking-mode features. The scope is explicitly marked as undecided, so first establish which requirements are accepted; done would mean implementing that agreed subset and verifying the mode on mobile devices.