Streamline README content; add useful links

- Remove Features and Concepts, Demos sections from README
  (this information is now on the website)

- Also remove the images used by the deleted "Features and Concepts" section
  (they're also on the website)

- Add Useful Links for docs, releases, community, and other key info
  (includes a link to the new splinter.dev/examples page)

- Fix line length

Signed-off-by: Anne Chenette <chenette@bitwise.io>

README.md

@@ -8,80 +8,19 @@ transactions between organizations. Splinter lets you combine blockchain-related
 technologies -- such as smart contracts and consensus engines -- to build a wide
 variety of architectural patterns.
 
-See [splinter.dev](https://www.splinter.dev/) for Splinter documentation,
-release notes, and community information.
+See [splinter.dev](https://www.splinter.dev/) to learn about Splinter.
 
- ⊹ [Features](#features-and-concepts) ⊹ [Building Splinter](#building-splinter) ⊹ [Demos](#demos) ⊹ [License](#license) ⊹
+## Useful Links
 
-## Features and Concepts
-
-Splinter allows the same network to do two-party private communication,
-multi-party private communication, and network-wide multi-party shared state,
-all managed with consensus. A Splinter network enables multi-party or two-party
-private conversations between nodes using circuits and services.
-
-  - A _**node**_ is the foundational runtime that allows an organization to
-  participate in the network.
-
-  - A _**circuit**_ is a virtual network within the broader Splinter network
-  that safely and securely enforces privacy scope boundaries.
-
-  - A _**service**_ is an endpoint within a circuit that sends and receives
-  private messages.
-
-A Splinter application provides a set of distributed services that can
-communicate with each other across a Splinter circuit.
-
-![Splinter private circuits with shared state](assets/diagram-splinter-circuits+3companies.svg)
-
-**Splinter is designed for privacy**
-
-The key concepts of Splinter are fundamentally anchored to privacy.
-
-   - _**Circuits**_ define scope and visibility domains.
-   - _**Shared state**_, a database updated by smart contracts, is visible only
-     to the services within a circuit.
-
-**Splinter is distributed and flexible**
-
-Splinter works across a network
-
-   - _**State agreement**_ is achieved via the Merkle-radix tree in
-     [Hyperledger Transact](https://github.com/hyperledger/transact/),
-     allowing multiple services to prove they have the same data down to the
-	 last bit, cryptographically.
-   - _**Consensus**_ is provided for creating real distributed applications.
-     Splinter currently includes **two-phase commit** for 2- or 3-party
-     conversations.
-   - _**Connections**_ are dynamically constructed between nodes as circuits are
-     created.
-
-
-![Splinter smart contract deployment at runtime](assets/diagram-splinter-smartcontractdeployment.svg)
-
-**Splinter is agile with smart contracts**
-
-   - Smart contracts _**capture business logic**_ for processing transactions.
-   - _**Runtime deployment**_ of smart contracts means no need to upgrade the
-     Splinter software stack to add business logic.
-   - _**Sandboxed WebAssembly smart contracts**_ keep the network safe and
-     ensure determinism.
-   - _**Scabbard**_, an out-of-the-box Splinter service that runs
-     [Sawtooth Sabre](https://github.com/hyperledger/sawtooth-sabre)
-     smart contracts across nodes, coordinated with consensus.
-
-**Splinter is designed for applications**
-
-   - _**State delta export**_ allows an application to materialize the
-     Merkle-radix tree database to another database such as PostgreSQL.
-     Applications can read from the materialized database (just like any other
-     web application).
-   - _**Admin services**_ provide applications with a REST API to dynamically
-     create new circuits, based on business need.
-   - _**Authorization**_ for circuit management can be delegated to application
-     code and defined by business policies.
-
-![Two-party Splinter circuit](assets/diagram-splinter-twopartycircuit.svg)
+* [Splinter documentation](https://www.splinter.dev/docs/)
+* [Release notes](https://www.splinter.dev/releases/)
+* [Community information](https://www.splinter.dev/community/)
+* [Other Splinter repositories](https://www.splinter.dev/community/repositories.html)
+* [Example applications](https://www.splinter.dev/examples/)
+* Related projects:
+    - [Hyperledger Grid](https://github.com/hyperledger/grid/)
+    - [Hyperledger Transact](https://github.com/hyperledger/transact/)
+    - [Sawtooth Sabre](https://github.com/hyperledger/sawtooth-sabre/)
 
 ## Building Splinter
 
@@ -112,19 +51,12 @@ example: `export 'CARGO_ARGS=-- --features experimental'`. To go back to
 building with default features, unset the environment variable:
 `unset CARGO_ARGS`
 
-## Demos
-
-Splinter includes an example application that you can run as a demo.
-[Gameroom](examples/gameroom/) is a web application that allows you to set up a
-dynamic multi-party circuit (called a "gameroom") and play tic tac toe (XO).
-
-For more information, see the [Gameroom
-README](https://github.com/Cargill/splinter/tree/master/examples/gameroom/README.md).
-
 ## License
 
-Splinter software is licensed under the [Apache License Version 2.0](LICENSE) software license.
+Splinter software is licensed under the [Apache License Version 2.0](LICENSE)
+software license.
 
 ## Code of Conduct
 
-Splinter operates under the [Cargill Code of Conduct](https://github.com/Cargill/code-of-conduct/blob/master/code-of-conduct.md).
+Splinter operates under the [Cargill Code of
+Conduct](https://github.com/Cargill/code-of-conduct/blob/master/code-of-conduct.md).