Align all the screenshots to the center

Author: rexim

README.md

@@ -2,7 +2,9 @@
 
 The Source Code from this YouTube Video:
 
-[![thumbnail](./imgs/thumbnail.png)](https://www.youtube.com/watch?v=qjWkNZ0SXfo)
+<p align=center>
+  [![thumbnail](./imgs/thumbnail.png)](https://www.youtube.com/watch?v=qjWkNZ0SXfo)
+</p>
 
 ## Quick Start
 
@@ -14,10 +16,14 @@ $ iexplore.exe ./index.html
 
 The repo is also deployed to GitHub Pages: [https://tsoding.github.io/formula/](https://tsoding.github.io/formula/)
 
-[![screenshot](./imgs/screenshot-400.png)](https://tsoding.github.io/formula/)
+<p align=center>
+  [![screenshot](./imgs/screenshot-400.png)](https://tsoding.github.io/formula/)
+</p>
 
 ## Model
 
 The model is provided by [https://github.com/Max-Kawula/penger-obj](https://github.com/Max-Kawula/penger-obj)
 
-[![penger-obj](./imgs/penger-obj.png)](https://github.com/Max-Kawula/penger-obj)
+<p align=center>
+  [![penger-obj](./imgs/penger-obj.png)](https://github.com/Max-Kawula/penger-obj)
+</p>