[UI] Define fix height to blog feed on the desktop view

[realslimshanky]

Blog feed does not have a constraint to limit how many posts should be visible on the page. This results in a long section captured by the feed div as seen below. This needs to look into and work asap.

[amitsin6h]

We need to also fix the image size

[realslimshanky]

@amitsin6h That can be fixed from the inpycon-blog. This issue concerns only the height.