Add NEU ESL to README.md (cotes2020#2441)

Embedded System Lab @ Northeastern University (NU-ESL) website recently
embraced Jekyll with al-folio theme. Add nuesl link to README.md

Author: jiangqucheng

README.md

@@ -151,6 +151,7 @@ Feel free to add your own page(s) by sending a PR.
 <a href="https://programming-group.com/" target="_blank">★</a>
 <a href="https://sailing-lab.github.io/" target="_blank">★</a>
 <a href="https://inbt.jhu.edu/epidiagnostics/" target="_blank">★</a>
+<a href="https://www.nuesl.org/" target="_blank">★</a>
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