Relocate Migration Guides from Configuration to Usage

Moves docs/configuration/migration/* to docs/usage/migration/* and the
'Startup Guides' nav block (New User Setup Guide + Migration Guides)
from Configuration to Usage, right after User Interface.

New User Setup Guide itself stays at
docs/configuration/new-user-setup.md -- only its nav entry moves.

Adds redirect_maps entries so old bookmarked/external links to
configuration/migration/*.md 301 to the new usage/migration/*.md
location instead of 404ing.

Updates cross-references in:
- docs/configuration/index.md (card removed)
- docs/configuration/new-user-setup.md (links updated)
- docs/install/index.md
- docs/install/build/mac/build.md

Content itself is essentially unchanged from the current Configuration
version -- verified by diffing against current dev; only internal
relative links within the migration files themselves needed
../../configuration/... prefixes added (since usage/migration/ and
configuration/migration/ are siblings of different parent dirs).

Extracted from #207 (tmhastings), commit 0d0ff11.

Independent of PR1/2/3 -- can merge in any order relative to those.

Author: Claude Assistant

docs/configuration/index.md

@@ -19,10 +19,4 @@ Please use the navigation menu :fontawesome-solid-bars:, search bar :fontawesome
 
     A compilation of all settings found in Trio with explanations and definitions
 
--   __[Migration Guides](migration/index.md)__
-
-    - - -
-    
-    Guidance on locating and identifying the necessary settings for onboarding
-
 </div>

docs/configuration/migration/aaps-migration.md

@@ -60,10 +60,10 @@ Trio has an Onboarding Wizard that walks you through these steps when you first
 !!! tip "Need help finding these settings in your current DIY app?"
     If you are coming from another Open Source Automated Insulin Dosing (OS-AID) app, these guides may help you with finding these settings in your previous app and inputing them into Trio.
 
-    - [Trio 0.2.x](migration/trio-02x-migration.md)
-    - [iAPS](migration/iaps-migration.md)
-    - [Loop](migration/loop-migration.md)
-    - [AndroidAPS](migration/aaps-migration.md)
+    - [Trio 0.2.x](../usage/migration/trio-02x-migration.md)
+    - [iAPS](../usage/migration/iaps-migration.md)
+    - [Loop](../usage/migration/loop-migration.md)
+    - [AndroidAPS](../usage/migration/aaps-migration.md)
 
 ## **Step 1:** Prepare Trio
 

docs/configuration/migration/iaps-migration.md

@@ -25,7 +25,7 @@
 
     The main branch is the preferred build for everyone except expert builders.
 
-    If you are coming from an older main version 0.2.x, please read the [Migration Guide](../../../configuration/migration/trio-02x-migration.md) before updating.
+    If you are coming from an older main version 0.2.x, please read the [Migration Guide](../../../usage/migration/trio-02x-migration.md) before updating.
 
     All Trio users are encouraged to follow along in [Trio Discord](https://discord.triodocs.org).
 

docs/configuration/migration/trio-02x-migration.md

@@ -11,7 +11,7 @@ Please use the navigation menu :fontawesome-solid-bars:, search bar :fontawesome
 !!! important "Attention Trio Users"
     The `main` branch is the preferred build for everyone except expert builders.
 
-    If you are coming from an older `main` version 0.2.x, please read the [Migration Guide](../configuration/migration/trio-02x-migration.md) before updating.
+    If you are coming from an older `main` version 0.2.x, please read the [Migration Guide](../usage/migration/trio-02x-migration.md) before updating.
 
 <div class="grid cards" markdown>