Re-integrate examples into the root workspace (#1466)

Co-authored-by: David Pedersen <[email protected]>

examples/customize-extractor-error/README.md

@@ -12,5 +12,5 @@ already existing extractors
 Run with
 
 ```sh
-cd examples && cargo run -p example-customize-extractor-error
+cargo run -p example-customize-extractor-error
 ```

examples/customize-extractor-error/src/main.rs

@@ -1,7 +1,7 @@
 //! Run with
 //!
 //! ```not_rust
-//! cd examples && cargo run -p example-customize-extractor-error
+//! cargo run -p example-customize-extractor-error
 //! ```
 
 mod custom_extractor;