add doi links

Author: NoushinN

README.md

@@ -5,6 +5,9 @@
 [![R](https://img.shields.io/badge/R-4.3%2B-blue)](https://www.r-project.org/)
 [![License: MIT](https://img.shields.io/badge/License-MIT-green.svg)](LICENSE)
 [![Website](https://img.shields.io/badge/Website-pkgdown-blue)](https://noushinn.github.io/emergenceModelR/)
+<!-- badges: start -->
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.20766770.svg)](https://doi.org/10.5281/zenodo.20766770)
+<!-- badges: end -->
 [![GitHub stars](https://img.shields.io/github/stars/NoushinN/emergenceModelR?style=social)](https://github.com/NoushinN/emergenceModelR)
 
 **emergenceModelR** is an educational R package for simulating, visualizing, and explaining simplified models of emergence, self-organization, complexity, cellular automata, agent interactions, and network growth.
@@ -217,4 +220,11 @@ For example:
 
 ## License
 
-MIT License
+MIT License
+
+## Citation
+
+If referencing this project, please cite: 
+
+Nabavi, N. *emergenceModelR: An Educational R Package for Simulating Simplified Models of Emergence and Complexity
+[[DOI](https://doi.org/10.5281/zenodo.20766770)

_pkgdown.yml

@@ -2,6 +2,16 @@ url: https://noushinn.github.io/emergenceModelR/
 
 template:
   bootstrap: 5
+  includes:
+    in_header: |
+      <!-- Google tag (gtag.js) -->
+      <script async src="https://www.googletagmanager.com/gtag/js?id=G-5LJV5S16HQ"></script>
+      <script>
+        window.dataLayer = window.dataLayer || [];
+        function gtag(){dataLayer.push(arguments);}
+        gtag('js', new Date());
+        gtag('config', 'G-5LJV5S16HQ');
+      </script>
 
 extra_css: pkgdown/extra.css
 
@@ -100,3 +110,4 @@ reference:
   contents:
   - measure_emergence
   - plot_emergence_sim
+