update the molecular rendering page

Author: Dou Du

_config.yml

@@ -41,3 +41,7 @@ sphinx:
   config:
     html_theme_options:
       search_bar_text: "Search this website..."
+
+parse:
+  myst_enable_extensions:
+    - html_image

extensions/molecular_rendering.md

@@ -23,7 +23,5 @@ However, it could still take hours to obtain the rendered images and videos.**
 
 * The electrostatic colormap of the benzene (C6H6) molecule
 
-![benzene1](./images/electrostatic_colormap.png)
-![benzene2](./images/electrostatic_trans.png)
-
-
+<img src="./images/electrostatic_colormap.png" alt="drawing" width="350"/>
+<img src="./images/electrostatic_trans.png" alt="drawing" width="350"/>