Flavors documentation update

[MiraMarshall]

Description of what this PR is changing or adding, and why:
Flavors staging site

This PR updates the flavors documentation.
Issues fixed by this PR (if any): Fixes #ISSUE-NUMBER

Presubmit checklist

• This PR doesn’t contain automatically generated corrections (Grammarly or similar).
• This PR follows the Google Developer Documentation Style Guidelines — for example, it doesn’t use i.e. or e.g., and it avoids I and we (first person).
• This PR uses semantic line breaks of 80 characters or fewer.

[domesticmouse]

This LGTM to me on the iOS side, but I'd like @jmagman's confirmation. I can't vouch for Android.

[domesticmouse]

Xcode is required for configuring Flavors for iOS.

Android Studio isn't strictly required for configuring Flavors for Android, but presumably is required for building an APK?

[sfshaza2]

Given that this doc has so many images, I'd like to see a staged version. Did you stage it? I should add that when we stage it, we generally put the staged URL in the PR, at the top.

[jmagman]

I think you're missing instructions related to the ios/Podfile when users have a plugin. Flutter plugins complicate this flow, it would be worth adding a plugin to the example to show what to do.

Particularly, ios/Podfile needs to be updated from

project 'Runner', {
  'Debug' => :debug,
  'Profile' => :release,
  'Release' => :release,
}

to

project 'Runner', {
  'Debug-development' => :debug,
  'Debug-production' => :debug,
  'Profile-development' => :release,
  'Profile-production' => :release,
  'Release-development' => :release,
  'Release-production' => :release,
}

[MaryaBelanger]

This is so well done! Some formatting suggestions to make it easier to follow

[MaryaBelanger]

LGTM!

Left comments for some minor formatting inconsistencies you may or may not already be aware of, I think they're intentional anyway because formatting was rendering weirdly

[sfshaza2]

Some of the feedback from my previous review hasn't been implemented. Let me know if you want to meet.

[sfshaza2]

I would like to land this before 2023. I think, once the edits are incorporated, it's good to go. Open an issue if there are any other "TODOs" that we want to incorporate. thx!

[sfshaza2]

lgtm. @jmagman, if you still have issues with this page, either let @MiraMarshall know or file an issue. I believe she's addressed your issues.

[jmagman]

I think this would be a lot clearer if the screenshots showed a paid flavor next to free as we have in our sample app, since only having one flavor doesn't really make sense since in that case you could just update the default app without dealing with flavors.

However I know you want to get this merged ASAP. LGTM once my two last comments are addressed.

[jmagman]

Suggested change

	"args": ["--flavor", "development", "--target", "lib/main_development.dart" ]
	"args": ["--flavor", "free", "--target", "lib/main_free.dart" ]

[jmagman]

There should already be a Bundle Display Name key in that file (casing is Info.plist). How about:

Suggested change

	Add the display name to **info.plist**. Create a new key in **info.plist** called **Bundle Display Name**
	with the value `$(PRODUCT_NAME)`.
	Add the display name to **Info.plist**. Update the **Bundle Display Name**
	value to `$(PRODUCT_NAME)`.

[MiraMarshall]

Thanks Jenn! I've made the changes and will address the screenshots with #7979