Update Template README (paritytech#12741)

* update README
remove matrix links
remove playground references (service reported as sunsetting)
OSPL rule per Docs style guide

* Apply suggestions from code review

Co-authored-by: Sacha Lansky <sacha@parity.io>

* Update README.md

* Apply suggestions from code review

Co-authored-by: lisa-parity <92225469+lisa-parity@users.noreply.github.com>

* (fix) chmod +x script

---------

Co-authored-by: Sacha Lansky <sacha@parity.io>
Co-authored-by: lisa-parity <92225469+lisa-parity@users.noreply.github.com>
Co-authored-by: parity-processbot <>

bin/node-template/README.md

@@ -171,6 +171,7 @@ Then run the following command to start a single node development chain.
 This command compiles the code and starts a local development network.
 You can also replace the default command (`cargo build --release && ./target/release/node-template --dev --ws-external`) by appending your own.
 Note: It is recommended to provide a custom `--base-path` to store the chain database.
+
 For example:
 
 ```sh