Fix broken links in README.md (#186)

Links would return 404 for the given URLs. I change the links to again
link to the correct file on Github.

Author: ten3roberts

color-eyre/README.md

@@ -211,9 +211,9 @@ For an example of how to setup custom filters, check out [`examples/custom_filte
 [`eyre::Result`]: https://docs.rs/eyre/*/eyre/type.Result.html
 [`Handler`]: https://docs.rs/color-eyre/*/color_eyre/struct.Handler.html
 [`examples/usage.rs`]: https://github.com/eyre-rs/color-eyre/blob/master/examples/usage.rs
-[`examples/custom_filter.rs`]: https://github.com/eyre-rs/eyre/tree/master/color-eyre/blob/master/examples/custom_filter.rs
-[`examples/custom_section.rs`]: https://github.com/eyre-rs/eyre/tree/master/color-eyre/blob/master/examples/custom_section.rs
-[`examples/multiple_errors.rs`]: https://github.com/eyre-rs/eyre/tree/master/color-eyre/blob/master/examples/multiple_errors.rs
+[`examples/custom_filter.rs`]: https://github.com/eyre-rs/eyre/blob/master/color-eyre/examples/custom_filter.rs
+[`examples/custom_section.rs`]: https://github.com/eyre-rs/eyre/blob/master/color-eyre/examples/custom_section.rs
+[`examples/multiple_errors.rs`]: https://github.com/eyre-rs/eyre/blob/master/color-eyre/examples/multiple_errors.rs
 
 #### License