update polkadot, substrate, cumulus readme (paritytech#1182)

* update readmes

* temporary ReadMe for the Polkadot SDK

* delete welcome readme

* update links on substrate readme

* update links on polkadot readme

* update links on cumulus readme

* update overseer feature comment

Co-authored-by: Liam Aharon <[email protected]>

* Update cumulus/README.md

Co-authored-by: Liam Aharon <[email protected]>

* Update cumulus/README.md

Co-authored-by: Liam Aharon <[email protected]>

* Update polkadot/README.md

Co-authored-by: Liam Aharon <[email protected]>

* Update polkadot/README.md

Co-authored-by: Liam Aharon <[email protected]>

* Update polkadot/README.md

Co-authored-by: Liam Aharon <[email protected]>

* update gitlab links

Co-authored-by: Liam Aharon <[email protected]>

* terminal friendly convention

---------

Co-authored-by: Liam Aharon <[email protected]>

Author: the-right-joyce

substrate/README.md

@@ -1,13 +1,44 @@
-Dear contributors and users,
+# Substrate · [![GitHub license](https://img.shields.io/badge/license-GPL3%2FApache2-blue)](#LICENSE) [![GitLab Status](https://gitlab.parity.io/parity/mirrors/polkadot-sdk/badges/master/pipeline.svg)](https://gitlab.parity.io/parity/mirrors/polkadot-sdk/-/pipelines) [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](docs/CONTRIBUTING.md) [![Stack Exchange](https://img.shields.io/badge/Substrate-Community%20&%20Support-24CC85?logo=stackexchange)](https://substrate.stackexchange.com/)
+<p align="center">
+  <img src="/docs/media/sub.gif">
+</p>
 
-We would like to inform you that we have recently made significant changes to our repository structure. In order to streamline our development process and foster better contributions, we have merged three separate repositories Cumulus, Substrate and Polkadot into a single new repository: [the Polkadot SDK](https://github.com/paritytech/polkadot-sdk). Go ahead and make sure to support us by giving a star ⭐️ to the new repo.
+Substrate is a next-generation framework for blockchain innovation 🚀.
 
-By consolidating our codebase, we aim to enhance collaboration and provide a more efficient platform for future development.
+## Getting Started
 
-If you currently have an open pull request in any of the merged repositories, we kindly request that you resubmit your PR in the new repository. This will ensure that your contributions are considered within the updated context and enable us to review and merge them more effectively.
+Head to [docs.substrate.io](https://docs.substrate.io) and follow the
+[installation](https://docs.substrate.io/install/) instructions.  Then try out one of the
+[tutorials](https://docs.substrate.io/tutorials/).  Refer to the [Docker instructions](./docker/README.md) to quickly run Substrate, Substrate Node Template, Subkey, or to build a chain spec.
 
-We appreciate your understanding and ongoing support throughout this transition. Should you have any questions or require further assistance, please don't hesitate to [reach out to us](https://forum.polkadot.network/t/psa-parity-is-currently-working-on-merging-the-polkadot-stack-repositories-into-one-single-repository/2883).
+## Community & Support
 
-Best Regards,
+Join the highly active and supportive community on the
+[Substrate Stack Exchange](https://substrate.stackexchange.com/) to ask questions about use and problems you run into using this software.  
+Please do report bugs and [issues here](https://github.com/paritytech/polkadot-sdk/issues) for anything you suspect requires action in the source.
 
-Parity Technologies
+## Contributions & Code of Conduct
+
+Please follow the contributions guidelines as outlined in
+[`docs/CONTRIBUTING.md`](https://github.com/paritytech/polkadot-sdk/blob/master/docs/CONTRIBUTING.md).
+In all communications and contributions, this project follows the [Contributor Covenant Code of Conduct](https://github.com/paritytech/polkadot-sdk/blob/master/docs/CODE_OF_CONDUCT.md).
+
+## Security
+
+The security policy and procedures can be found in
+[`docs/SECURITY.md`](https://github.com/paritytech/polkadot-sdk/blob/master/docs/SECURITY.md).
+
+## License
+
+- Substrate Primitives (`sp-*`), Frame (`frame-*`) and the pallets (`pallets-*`), binaries (`/bin`)
+and all other utilities are licensed under [Apache 2.0](LICENSE-APACHE2).  - Substrate Client
+(`/client/*` / `sc-*`) is licensed under [GPL v3.0 with a classpath linking
+exception](LICENSE-GPL3).
+
+The reason for the split-licensing is to ensure that for the vast majority of teams using Substrate
+to create feature-chains, then all changes can be made entirely in Apache2-licensed code, allowing
+teams full freedom over what and how they release and giving licensing clarity to commercial teams.
+
+In the interests of the community, we require any deeper improvements made to Substrate's core logic
+(e.g. Substrate's internal consensus, crypto or database code) to be contributed back so everyone
+can benefit.