SDL_ttf: Update INTRO-cmake.md

SDL Commits
1 
From d554beec4e9a72a836e23aa815a54cc1dd2c5f3e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Oskar=20Biedro=C5=84?=
 <47087484+bozgi@users.noreply.github.com>
Date: Fri, 28 Mar 2025 18:23:48 +0100
Subject: [PATCH] Update INTRO-cmake.md

Use vendored libraries
---
 docs/INTRO-cmake.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/docs/INTRO-cmake.md b/docs/INTRO-cmake.md
index fb84c9ca..556505f8 100644
--- a/docs/INTRO-cmake.md
+++ b/docs/INTRO-cmake.md
@@ -15,6 +15,9 @@ project(hello)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/$<CONFIGURATION>")
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/$<CONFIGURATION>")
 
+# Use vendored libs
+set(SDLTTF_VENDORED ON)
+
 # This assumes the SDL source is available in vendored/SDL
 add_subdirectory(vendored/SDL EXCLUDE_FROM_ALL)