Expand coverage of applications and their lifecycles

[dgeb]

While working on #789, I've come to realize that the entire "Services and Initializers" section needs a refresh.

I propose that we expand this section to cover applications, application instances, registrations (via RegistryProxy methods) as well as lookups (via ContainerProxy methods).

This whole section should probably be titled something like "Application Lifecycle" or simply "Applications" with subsections such as:

• Applications and instances
• Registrations and lookups
• Initializers [covering both application and instance initializers]
• Services

Open to suggestions here. I will do what's needed to launch the registry / container reform this week, but I also feel that much of this is needed to put the changes in the proper context.

[dgeb]

And of course this area of the guides is also directly related to the engines work I'm starting.

[michaelrkn]

This sounds great!

[michaelrkn]

I like "Application Lifecycle" - @locks what do you think? Let's settle on it before 2.1 Guides are released so we don't bork version switching when 2.2 come out.

[dgeb]

I like "Application Lifecycle"

I've been working on this a bit today and came up with "Application Concerns" as an alternative umbrella term. I thought this might be more inclusive of Services (although it's arguable that Services should just be moved into a separate section instead).

[michaelrkn]

Yeah, and "lifecycle" implies death of applications too ;) I don't know about "concerns"... I don't have super strong feelings though.

[dgeb]

Hmmm ... I share your concerns about "concerns". It's rather generic, but this is a grab bag of application-related topics after all. I suppose I could just use /applications/ as the URL slug to start and then we could change the title text to anything application-related later.

[michaelrkn]

Good thinking on the slug!