add links to SHA-256 hashes

README.md

@@ -12,3 +12,16 @@ https://www.gyan.dev/ffmpeg/builds/tools-version
 https://www.gyan.dev/ffmpeg/builds/last-build-update  
 https://www.gyan.dev/ffmpeg/builds/next-build-update  
 https://www.gyan.dev/ffmpeg/builds/changelog-counter  
+
+
+To obtain SHA-256 hashes for the latest releases, fetch these plaintext files
+
+https://www.gyan.dev/ffmpeg/builds/sha256-git-full  
+https://www.gyan.dev/ffmpeg/builds/sha256-git-essentials  
+https://www.gyan.dev/ffmpeg/builds/sha256-release-full  
+https://www.gyan.dev/ffmpeg/builds/sha256-release-essentials-7z  
+https://www.gyan.dev/ffmpeg/builds/sha256-release-essentials-zip  
+https://www.gyan.dev/ffmpeg/builds/sha256-release-full-shared  
+https://www.gyan.dev/ffmpeg/builds/sha256-tools  
+
+All hashes are for the 7-zip archives unless marked otherwise in the URL.