adding citation and paper badge!

CITATION.cff

@@ -0,0 +1,48 @@
+cff-version: "1.2.0"
+authors:
+- family-names: Soroka
+  given-names: Emiko
+  orcid: "https://orcid.org/0009-0001-2710-469X"
+- family-names: Kochenderfer
+  given-names: Mykel J.
+  orcid: "https://orcid.org/0000-0002-7238-9663"
+- family-names: Lall
+  given-names: Sanjay
+  orcid: "https://orcid.org/0000-0002-1783-5309"
+contact:
+- family-names: Soroka
+  given-names: Emiko
+  orcid: "https://orcid.org/0009-0001-2710-469X"
+- family-names: Kochenderfer
+  given-names: Mykel J.
+  orcid: "https://orcid.org/0000-0002-7238-9663"
+- family-names: Lall
+  given-names: Sanjay
+  orcid: "https://orcid.org/0000-0002-1783-5309"
+doi: 10.6084/m9.figshare.26768461
+message: If you use this software, please cite our article in the
+  Journal of Open Source Software.
+preferred-citation:
+  authors:
+  - family-names: Soroka
+    given-names: Emiko
+    orcid: "https://orcid.org/0009-0001-2710-469X"
+  - family-names: Kochenderfer
+    given-names: Mykel J.
+    orcid: "https://orcid.org/0000-0002-7238-9663"
+  - family-names: Lall
+    given-names: Sanjay
+    orcid: "https://orcid.org/0000-0002-1783-5309"
+  date-published: 2024-08-20
+  doi: 10.21105/joss.06757
+  issn: 2475-9066
+  issue: 100
+  journal: Journal of Open Source Software
+  publisher:
+    name: Open Journals
+  start: 6757
+  title: "Satisfiability.jl: Satisfiability Modulo Theories in Julia"
+  type: article
+  url: "https://joss.theoj.org/papers/10.21105/joss.06757"
+  volume: 9
+title: "Satisfiability.jl: Satisfiability Modulo Theories in Julia"

README.md

@@ -1,6 +1,6 @@
 # [Satisfiability.jl](https://elsoroka.github.io/Satisfiability.jl)
 
-[![build status](https://github.com/elsoroka/Satisfiability.jl/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/elsoroka/Satisfiability.jl/actions/workflows/CI.yml?query=branch%3Amain) [![docs](https://github.com/elsoroka/Satisfiability.jl/actions/workflows/docs.yml/badge.svg)](https://elsoroka.github.io/Satisfiability.jl/) [![codecov](https://codecov.io/gh/elsoroka/Satisfiability.jl/branch/main/graph/badge.svg?token=84BIREQL46)](https://codecov.io/gh/elsoroka/Satisfiability.jl)
+[![build status](https://github.com/elsoroka/Satisfiability.jl/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/elsoroka/Satisfiability.jl/actions/workflows/CI.yml?query=branch%3Amain) [![docs](https://github.com/elsoroka/Satisfiability.jl/actions/workflows/docs.yml/badge.svg)](https://elsoroka.github.io/Satisfiability.jl/) [![codecov](https://codecov.io/gh/elsoroka/Satisfiability.jl/branch/main/graph/badge.svg?token=84BIREQL46)](https://codecov.io/gh/elsoroka/Satisfiability.jl) [![DOI](https://joss.theoj.org/papers/10.21105/joss.06757/status.svg)](https://doi.org/10.21105/joss.06757)
 
 Satisfiability.jl is a package for representing satisfiability modulo theories (SMT) problems in Julia. This package provides a simple front-end interface to common SMT solvers, including full support for vector-valued and matrix-valued expressions. Currently, the theories of propositional logic, uninterpreted functions, Integers, Reals and fixed-size BitVectors are supported. We will eventually add support for all [SMT-LIB standard theories](http://smtlib.cs.uiowa.edu/theories.shtml).
 
@@ -89,4 +89,4 @@ println(status) # if status is UNSAT we proved it.
 Release 0.1.2 is out! You can install it with the command `using Pkg; Pkg.add("Satisfiability")`. Please help make the Julia ecosystem better for everyone by opening a GitHub issue if you have feedback or find a bug.
 
 ## Contributing
-Contribution guidelines are [here](https://elsoroka.github.io/Satisfiability.jl/dev/contributing/). If you're not sure how to get started, take a look at the [Roadmap](https://github.com/elsoroka/Satisfiability.jl/issues/46) and anything tagged [help wanted](https://github.com/elsoroka/Satisfiability.jl/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22).
+Contribution guidelines are [here](https://elsoroka.github.io/Satisfiability.jl/dev/contributing/). If you're not sure how to get started, take a look at the [Roadmap](https://github.com/elsoroka/Satisfiability.jl/issues/46) and anything tagged [help wanted](https://github.com/elsoroka/Satisfiability.jl/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22).