docs: centralize and update wiki documentation (#1279)

* docs: centralize documentation into wiki/

Move scattered docs into wiki/ for a single documentation hub:
- MIGRATION_GUIDE.md -> wiki/migration-v2.md
- examples/README.md -> wiki/e2e-overview.md
- examples/SHARED_E2E_SETUP.md -> wiki/e2e-setup.md
- examples/CHANGELOG.md -> wiki/e2e-changelog.md (new)
- examples/NEW_ARCH_MIGRATION.md -> wiki/new-arch-migration.md (new)
- Add wiki/README.md index

Keep project READMEs (e2e-compat, e2e-latest, e2e-shared) in place since
they're meant to be copied with the example apps.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: remove outdated wiki pages and fix broken links

Delete wiki/nix.md and wiki/scripts.md which documented removed
infrastructure (nix flake, scripts/ directory, shells/ configs).
Rewrite wiki/devbox.md to reflect the current per-app devbox setup
with the mobile-devtools plugin. Fix root README link to migration
guide (moved to wiki/) and add wiki pointer in Contributing section.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: fix table of contents links in root README

Flatten the ToC to top-level section links only. The previous deeply
nested structure with a self-referential parent item wasn't rendering
as clickable links on GitHub.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: organize wiki into subfolders

Move E2E docs into wiki/e2e/ and migration guides into wiki/guides/
for better discoverability. Update all links in wiki/README.md and
root README.md.

wiki/
├── README.md
├── devbox.md
├── release.md
├── e2e/
│   ├── overview.md
│   ├── setup.md
│   └── changelog.md
└── guides/
    ├── migration-v2.md
    └── new-arch-migration.md

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: abueide

README.md

@@ -10,52 +10,17 @@ The hassle-free way to add Segment analytics to your React-Native app.
 
 ## Table of Contents
 
-- [@segment/analytics-react-native](#segmentanalytics-react-native)
-  - [Table of Contents](#table-of-contents)
-  - [Installation](#installation)
-    - [Expo](#expo)
-    - [Permissions](#permissions)
-  - [Migrating](#migrating)
-  - [Usage](#usage)
-    - [Setting up the client](#setting-up-the-client)
-    - [Client Options](#client-options)
-    - [iOS Deep Link Tracking Setup](#ios-deep-link-tracking-setup)
-    - [Native AnonymousId](#native-anonymousid)
-    - [Usage with hooks](#usage-with-hooks)
-    - [useAnalytics()](#useanalytics)
-    - [Usage without hooks](#usage-without-hooks)
-  - [Client methods](#client-methods)
-    - [Track](#track)
-    - [Screen](#screen)
-    - [Identify](#identify)
-    - [Group](#group)
-    - [Alias](#alias)
-    - [Reset](#reset)
-    - [Flush](#flush)
-    - [(Advanced) Cleanup](#advanced-cleanup)
-  - [Automatic screen tracking](#automatic-screen-tracking)
-    - [React Navigation](#react-navigation)
-    - [React Native Navigation](#react-native-navigation)
-  - [Consent Management](#consent-management)
-    - [Segment CMP](#segment-managed-cmp)
-    - [Event Stamping](#event-stamping)
-    - [Segment Consent Preference Updated Event](#segment-consent-preference-updated-event)
-    - [Event Flow](#event-flow)
-    - [Getting Started](#getting-started)
-  - [Plugins + Timeline architecture](#plugins--timeline-architecture)
-    - [Plugin Types](#plugin-types)
-    - [Destination Plugins](#destination-plugins)
-    - [Adding Plugins](#adding-plugins)
-    - [Writing your own Plugins](#writing-your-own-plugins)
-    - [Supported Plugins](#supported-plugins)
-  - [Controlling Upload With Flush Policies](#controlling-upload-with-flush-policies)
-  - [Adding or removing policies](#adding-or-removing-policies)
-    - [Creating your own flush policies](#creating-your-own-flush-policies)
-  - [Handling errors](#handling-errors)
-    - [Reporting errors from plugins](#reporting-errors-from-plugins)
-  - [Contributing](#contributing)
-  - [Code of Conduct](#code-of-conduct)
-  - [License](#license)
+- [Installation](#installation)
+- [Migrating](#migrating)
+- [Usage](#usage)
+- [Client methods](#client-methods)
+- [Automatic screen tracking](#automatic-screen-tracking)
+- [Consent Management](#consent-management)
+- [Plugins + Timeline architecture](#plugins--timeline-architecture)
+- [Controlling Upload With Flush Policies](#controlling-upload-with-flush-policies)
+- [Handling errors](#handling-errors)
+- [Contributing](#contributing)
+- [License](#license)
 
 ## Installation
 
@@ -98,7 +63,7 @@ In your app's `AndroidManifest.xml` add the below line between the `<manifest>`
 
 ## Migrating
 
-See the [Migration Guide](MIGRATION_GUIDE.md) for a detailed walkthrough of the changes you will need to make when upgrading to `analytics-react-native 2.0`
+See the [Migration Guide](wiki/guides/migration-v2.md) for a detailed walkthrough of the changes you will need to make when upgrading to `analytics-react-native 2.0`
 
 ## Usage
 
@@ -929,7 +894,7 @@ try {
 
 ## Contributing
 
-See the [contributing guide](CONTRIBUTING.md) to learn how to contribute to the repository and the development workflow.
+See the [contributing guide](CONTRIBUTING.md) to learn how to contribute to the repository and the development workflow. Internal documentation for development environment setup, E2E testing, and releases is in the [wiki](wiki/README.md).
 
 ## Code of Conduct