Update README.md

update with contributing information and remove redundant license information

Author: parispittman

README.md

@@ -162,11 +162,29 @@ Technical documentation is available at
 [llbuild.readthedocs.io](https://llbuild.readthedocs.io).
 
 
-Bug Reports
------------
+Contributing to /swift-llbuild
+-------------
+
+Contributions to /swift-llbuild are welcomed and encouraged! Please see the
+[Contributing to Swift guide](https://swift.org/contributing/).
+
+Before submitting the pull request, please make sure you have [tested your
+ changes](https://github.com/apple/swift/blob/main/docs/ContinuousIntegration.md)
+ and that they follow the Swift project [guidelines for contributing
+ code](https://swift.org/contributing/#contributing-code). Bug reports should be 
+ filed in [the issue tracker](https://github.com/apple/swift-llbuild/issues) of 
+ `swift-llbuild` repository on GitHub.
 
-Bug reports should be filed in [the issue tracker](https://github.com/apple/swift-llbuild/issues) of `swift-llbuild` repository on GitHub.
+To be a truly great community, [Swift.org](https://swift.org/) needs to welcome
+developers from all walks of life, with different backgrounds, and with a wide
+range of experience. A diverse and friendly community will have more great
+ideas, more unique perspectives, and produce more great code. We will work
+diligently to make the Swift community welcoming to everyone.
 
+To give clarity of what is expected of our members, Swift has adopted the
+code of conduct defined by the Contributor Covenant. This document is used
+across many open source communities, and we think it articulates our values
+well. For more, see the [Code of Conduct](https://swift.org/code-of-conduct/).
 
 Open Projects
 -------------
@@ -261,10 +279,4 @@ and [Salsa](https://github.com/salsa-rs/salsa).
 
 License
 -------
-
-Copyright (c) 2014 - 2022 Apple Inc. and the Swift project authors.
-Licensed under Apache License v2.0 with Runtime Library Exception.
-
 See https://swift.org/LICENSE.txt for license information.
-
-See https://swift.org/CONTRIBUTORS.txt for Swift project authors.