Fix links in CONTRIBUTING.md

Author: antoyo

CONTRIBUTING.md

@@ -6,7 +6,7 @@ Welcome to the `rustc_codegen_gcc` project! This guide will help you get started
 
 ### Setting Up Your Development Environment
 
-For detailed setup instructions including dependencies, build steps, and initial testing, please refer to our [README](https://github.com/rust-lang/rustc_codegen_gcc/blob/master/Readme.md). The README contains the most up-to-date information on:
+For detailed setup instructions including dependencies, build steps, and initial testing, please refer to our [README](Readme.md). The README contains the most up-to-date information on:
 
 - Required dependencies and system packages
 - Repository setup and configuration
@@ -49,14 +49,14 @@ The project provides several environment variables for debugging:
 - `CG_GCCJIT_DUMP_MODULE`: Dumps a specific module
 - `CG_GCCJIT_DUMP_TO_FILE`: Creates C-like representation
 
-Full list of debugging options can be found in the [README](/rust-lang/rustc_codegen_gcc#env-vars).
+Full list of debugging options can be found in the [README](Readme.md#env-vars).
 
 ## Making Contributions
 
 ### Finding Issues to Work On
-1. Look for issues labeled with [`good first issue`](/rust-lang/rustc_codegen_gcc/issues?q=is%3Aissue state%3Aopen label%3A"good first issue") or [`help wanted`](/rust-lang/rustc_codegen_gcc/issues?q=is%3Aissue state%3Aopen label%3A"help wanted")
+1. Look for issues labeled with [`good first issue`](https://github.com/rust-lang/rustc_codegen_gcc/issues?q=is%3Aissue state%3Aopen label%3A"good first issue") or [`help wanted`](https://github.com/rust-lang/rustc_codegen_gcc/issues?q=is%3Aissue state%3Aopen label%3A"help wanted")
 2. Check the [progress report](https://blog.antoyo.xyz/rustc_codegen_gcc-progress-report-34#state_of_rustc_codegen_gcc) for larger initiatives
-3. Consider improving documentation or investigating [failing tests](https://github.com/rust-lang/rustc_codegen_gcc/tree/master/tests)(except `failing-ui-tests12.txt`)
+3. Consider improving documentation or investigating [failing tests](https://github.com/rust-lang/rustc_codegen_gcc/tree/master/tests) (except `failing-ui-tests12.txt`)
 
 ### Pull Request Process
 1. Fork the repository and create a new branch
@@ -75,12 +75,12 @@ Full list of debugging options can be found in the [README](/rust-lang/rustc_cod
 - [Rustc Dev Guide](https://rustc-dev-guide.rust-lang.org/)
 - [GCC Internals Documentation](https://gcc.gnu.org/onlinedocs/gccint/)
 - Project-specific documentation in the `doc/` directory:
-  - [Common errors](/rust-lang/rustc_codegen_gcc/blob/master/doc/errors.md)
-  - [Debugging](/rust-lang/rustc_codegen_gcc/blob/master/doc/debugging.md)
-  - [Debugging libgccjit](/rust-lang/rustc_codegen_gcc/blob/master/doc/debugging-libgccjit.md)
-  - [Git subtree sync](/rust-lang/rustc_codegen_gcc/blob/master/doc/subtree.md)
-  - [List of useful commands](/rust-lang/rustc_codegen_gcc/blob/master/doc/tips.md)
-  - [Send a patch to GCC](/rust-lang/rustc_codegen_gcc/blob/master/doc/sending-gcc-patch.md)
+  - [Common errors](doc/errors.md)
+  - [Debugging](doc/debugging.md)
+  - [Debugging libgccjit](doc/debugging-libgccjit.md)
+  - [Git subtree sync](doc/subtree.md)
+  - [List of useful commands](doc/tips.md)
+  - [Send a patch to GCC](doc/sending-gcc-patch.md)
 
 ## Getting Help