SDL: README-migration.md: Removed obsolete documentation.

SDL Commits
1 
From d8c7006a426c3fc67d3958d2f7eeb6cb2e59c02e Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Mon, 6 Jan 2025 13:07:21 -0500
Subject: [PATCH] README-migration.md: Removed obsolete documentation.

Fixes #11434.
---
 docs/README-migration.md | 2 --
 1 file changed, 2 deletions(-)

diff --git a/docs/README-migration.md b/docs/README-migration.md
index ad5886f95d100..daa7af2eef16e 100644
--- a/docs/README-migration.md
+++ b/docs/README-migration.md
@@ -399,8 +399,6 @@ should be changed to:
     SDL_Keymod mod = event.key.mod;

-The keycode in key events is affected by modifiers by default. e.g. pressing the A key would generate the keycode SDLK_A, or ‘a’, and pressing it while holding the shift key would generate the keycode SDLK_A, or ‘A’. This behavior can be customized with SDL_HINT_KEYCODE_OPTIONS.

The gamepad event structures caxis, cbutton, cdevice, ctouchpad, and csensor have been renamed gaxis, gbutton, gdevice, gtouchpad, and gsensor.

The mouseX and mouseY fields of SDL_MouseWheelEvent have been renamed mouse_x and mouse_y.