fix non-breaking space and imges' preview

README.md

@@ -1,11 +1,8 @@
 # Hopfield OCR
 Hopfield network implementation + visualization of its energy landscape as seen in Artificial Systems module ([https://github.com/mc-cat-tty/SistemiArtificiali/](https://github.com/mc-cat-tty/SistemiArtificiali/))
 
-## Preview
-[Energy landscape with spurious patterns](img/img1.png)
-
-[Energy landscape and NN](img/img2.png)
-
-[Only descending energy landscape](img/img3.png)
-
-[OCR energy plot](img/img4.png)
+## Preview
+![Energy landscape with spurious patterns](img/img1.png)
+![Energy landscape and NN](img/img2.png)
+![Only descending energy landscape](img/img3.png)
+![OCR energy plot](img/img4.png)