v5.x-migrate-to-2.13: CONTRIBUTING.md instructions

CONTRIBUTING.md

@@ -1,11 +1,44 @@
+# Contributing 
+
 ## Building
 
-Clone the repository and then run tests.
+Clone the repository.
+
+```shell
+$ git clone git@github.com:ScorexFoundation/sigmastate-interpreter.git
+$ cd sigmastate-interpreter
+$ sbt test
+```
+
+Then you can compile the library with SBT and run tests.
+
+```shell
+$ sbt
+sbt:sigma-state> compile
+sbt:sigma-state> test
+```
+
+By default SBT uses Scala 2.12 for compilation and running tests. To compile for Scala 2.13 use the following commands:
+
+```shell
+$ sbt
+sbt:sigma-state> ++2.13.8
+sbt:sigma-state> compile
+sbt:sigma-state> test
+```
+
+You can also run SBT commands for all Scala versions at once:
+
+```shell
+$ sbt
+sbt:sigma-state> +compile
+sbt:sigma-state> +test
+```
+
+To run specific test suite use the following command:
 
 ```shell
-git clone git@github.com:ScorexFoundation/sigmastate-interpreter.git
-cd sigmastate-interpreter
-sbt test
+sbt:sigma-state> testOnly <full test class name>
 ```
 
 ## Releasing

README.md

@@ -111,6 +111,35 @@ libraryDependencies += "org.scorexfoundation" %% "sigma-state" % "4.0.3"
 | sigma-library | Implementation of graph IR nodes for Sigma types   |
 | sigmastate | Implementation ErgoTree, Interpreter and cost estimation   |
 
+## Contributing
+
+We welcome contributions to this project! If you are interested in contributing, here are
+a few ways to get started:
+
+**Report bugs:** If you have found a bug please open an issue on the issue tracker.
+
+**Fix bugs or implement features:** If you would like to fix a bug or implement a new
+feature, please fork the repository and open a pull request with your changes. Please make
+sure to include a clear description of the changes you have made and why you think they
+should be included in the project.
+
+**Improve documentation:** If you notice that the documentation could be improved, please
+feel free to make changes and open a pull request.
+
+**Review pull requests:** If you would like to help review pull requests, please take a
+look at the open pull requests and leave comments on any that you would like to review.
+
+Before you start working on a contribution, please make sure to read the [contributing
+guidelines](CONTRIBUTING.md). These documents outline the expectations for contributions
+to this project.
+
+Thank you for your interest in contributing to this project! Your help is always appreciated!
+
+
+
+Please submit a pull request or create an issue to add a new cryptographic primitives or better implementations.
+
+
 ## Acknowledgments
 
 We thank JetBrains for [supporting](https://www.jetbrains.com/buy/opensource/) this project since 2021 by providing All Products Pack subscription.