docs: fix cargo c links in README

Two of them were broken because I forgot to pull out the anchor target.

Author: cpu

README.md

@@ -23,7 +23,7 @@ to provide the cryptographic primitives.
 
 To build rustls-ffi as a static or shared library you'll need to [install the
 Rust toolchain](https://rustup.rs/) (version 1.71 or above) as well as 
-[cargo c](https://github.com/lu-zero/cargo-c).
+[cargo-c].
 
 The [cargo-c] tool can be installed from 
 [your package manager](https://github.com/lu-zero/cargo-c?tab=readme-ov-file#availability)
@@ -33,6 +33,8 @@ If you plan to build the `client` and `server` [C examples](#example-application
 you will also need `cmake` and a C compiler (`gcc` and `clang` should both work, 
 as well as MSVC on Windows).
 
+[cargo-c]: https://github.com/lu-zero/cargo-c
+
 ## Building and Installing
 
 ```bash
@@ -42,7 +44,7 @@ sudo cargo capi install --release
 ```
 
 If you receive a message like "error: no such command capi" you need to install
-[cargo c] from your package manager, or using `cargo install cargo-c`.
+[cargo-c] from your package manager, or using `cargo install cargo-c`.
 
 To change where the library is installed, use `--prefix` like: