doc(msrv); update msrv

README.md

@@ -276,16 +276,17 @@ for migration instructions.
 
 When building against nightly Rust, the following MSRV policy is enforced for unstable library features.
 
-* Windows and macOS: **latest** nightly
-* Linux: **1.76**
+* All platforms: **1.78**
 
 A CI job runs weekly to ensure librashader continues to build on nightly. 
 
-Building against stable Rust requires a higher MSRV.
-* All platforms: **1.77**
+When building against stable Rust with the `stable` feature, the following MSRV policy is enforced.
 
-Note that the MSRV is only intended to ease distribution on Linux when building against nightly Rust or with `RUSTC_BOOTSTRAP=1`, and is allowed to change any time. 
+* All platforms: **1.78**
+
+Note that the MSRV is only intended to ease distribution on Linux and is allowed to change any time. 
 It generally tracks the latest version of Rust available in the latest version of Ubuntu, but this may change with no warning in a patch release.
+Building on Debian 12 requires `rustc-web`.
 
 ## License
 The core parts of librashader such as the preprocessor, the preset parser, 
@@ -307,4 +308,4 @@ The end user must obtain the implementation of librashader themselves. For more
 see the [MPL 2.0 FAQ](https://www.mozilla.org/en-US/MPL/2.0/FAQ/).
 
 
-At your discretion, you may instead choose to distribute `librashader` under the terms of GPLv3 rather than MPL-2.0.
+At your discretion, you may instead choose to distribute `librashader` under the terms of GPLv3 rather than MPL-2.0.