change bash to sh

Author: Miller

src/linkage.md

@@ -151,13 +151,13 @@ feature. These target features are typically configured from the command line
 via flags to the compiler itself. For example to enable a static runtime you
 would execute:
 
-```bash
+```sh
 rustc -C target-feature=+crt-static foo.rs
 ```
 
 whereas to link dynamically to the C runtime you would execute:
 
-```bash
+```sh
 rustc -C target-feature=-crt-static foo.rs
 ```
 
@@ -206,7 +206,7 @@ To use this feature locally, you typically will use the `RUSTFLAGS` environment
 variable to specify flags to the compiler through Cargo. For example to compile
 a statically linked binary on MSVC you would execute:
 
-```bash
+```sh
 RUSTFLAGS='-C target-feature=+crt-static' cargo build --target x86_64-pc-windows-msvc
 ```