Add Zulip links to README

README.md

@@ -1,55 +1,58 @@
 # Welcome!
 
-This is the official repository for the [Soufflé](https://souffle-lang.github.io) language project.  
-The Soufflé language is similar to Datalog (but has terms known as records), and is frequently used as a 
-domain-specific language for analysis problems. 
+This is the official repository for the [Soufflé](https://souffle-lang.github.io) language project.
+The Soufflé language is similar to Datalog (but has terms known as records), and is frequently used as a
+domain-specific language for analysis problems.
 
 [![License: UPL](https://img.shields.io/badge/License-UPL--1.0-blue.svg)](https://github.com/souffle-lang/souffle/blob/master/LICENSE)
+[![Zulip chat](https://img.shields.io/badge/zulip-join_chat-brightgreen.svg)](https://souffle.zulipchat.com)
 [![Build Status](https://travis-ci.org/souffle-lang/souffle.svg?branch=master)](https://travis-ci.org/souffle-lang/souffle)
 [![codecov](https://codecov.io/gh/souffle-lang/souffle/branch/master/graph/badge.svg)](https://codecov.io/gh/souffle-lang/souffle)
 
 ## Features of Soufflé
 
 *   Efficient translation to parallel C++ of Datalog programs
-*   Efficient interpretation  
-*   Extended semantics of Datalog, e.g., permitting unbounded recursions with numbers and terms 
-*   Simple component model for Datalog specifications 
-*   Recursively defined record types (aka. constructors) for tuples 
+*   Efficient interpretation
+*   Extended semantics of Datalog, e.g., permitting unbounded recursions with numbers and terms
+*   Simple component model for Datalog specifications
+*   Recursively defined record types (aka. constructors) for tuples
 
 ## How to get Soufflé
- 
-Use git to obtain the source code of Soufflé. 
+
+Use git to obtain the source code of Soufflé.
 
     $ git clone git://github.com/souffle-lang/souffle.git
-    
+
 Build instructions can be found [here](https://souffle-lang.github.io/build).
 
 ## Legacy code
 
-If you have written code for an older version of Souffle, please use the command line flag `--legacy`. 
+If you have written code for an older version of Souffle, please use the command line flag `--legacy`.
 Alternatively, please add the following line to the start of your source-code:
 ```
 .pragma "legacy"
 ```
 
 ## How to contribute
 
-Issues and bug reports for Souffle are found in the [issue list](https://github.com/souffle-lang/souffle/issues). 
+Issues and bug reports for Souffle are found in the [issue list](https://github.com/souffle-lang/souffle/issues).
 This list is also where new contributors may find extensions / bug fixes to work on.
 
 To contribute in this repo, please open a pull request from your fork of this repository.
 The general workflow is as follows.
 
 1. Find an issue in the issue list.
 2. Fork the [souffle-lang/souffle](http://github.com/souffle-lang/souffle.git) repo.
-3. Push your changes to a branch in your forked repo. 
+3. Push your changes to a branch in your forked repo.
 4. Submit a pull request to souffle-lang/souffle from your forked repo.
-Our continuous integration framework enforces coding guidelines with the help of clang-format and clang-tidy. 
+Our continuous integration framework enforces coding guidelines with the help of clang-format and clang-tidy.
 
 For more information on building and developing Souffle, please read the [developer tutorial](https://souffle-lang.github.io/development).
 
 ## [Home Page](https://souffle-lang.github.io)
 
+## [Zulip Chat](https://souffle.zulipchat.com)
+
 ## [Documentation](https://souffle-lang.github.io/docs.html)
 
 ## [Contributors](https://souffle-lang.github.io/contributors)