[RFC] Add partner application process to ECOSYSTEM.md

[rickhanlonii]

Overview

This PR updates the ECOSYSTEM.md with more information for how to apply to be a partner, and includes an update to the joining process including a 3 month incubation period.

It also emphasizes that being a partner is a commitment of resources to improve React Native, and not a status symbol.

Changelog: internal

[github-actions[bot]]

	Fails
:no_entry_sign:	:clipboard: Verify Changelog Format - See Changelog format

	Warnings
:warning:	:clipboard: Missing Summary - Can you add a Summary? To do so, add a "## Summary" section to your PR description. This is a good place to explain the motivation for making this change.
:warning:	:clipboard: Missing Test Plan - Can you add a Test Plan? To do so, add a "## Test Plan" section to your PR description. A Test Plan lets us know how these changes were tested.

Generated by :no_entry_sign: dangerJS against 009f95142e2d379f9a776f83e4468eee120a3e47

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	8,744,350	-225,902
android	hermes	armeabi-v7a	8,056,503	-174,945
android	hermes	x86	9,235,453	-248,466
android	hermes	x86_64	9,086,268	-240,123
android	jsc	arm64-v8a	9,307,098	-224,016
android	jsc	armeabi-v7a	8,496,599	-173,042
android	jsc	x86	9,369,085	-246,578
android	jsc	x86_64	9,623,994	-238,237

Base commit: 0201e51bbe46219458f01cf5bfe67840bdde8d33 Branch: main

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@rickhanlonii has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@rickhanlonii has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[github-actions[bot]]

This pull request was successfully merged by @rickhanlonii in 9e1c3d266ae820b586cb75b1eff1f4d61d22aa19.

^{When will my fix make it into a release? | Upcoming Releases}