Add custom directive to render TLDR similar to list-table

[xames3]

• Need to come up with a new custom directive which can render list-table like table but for TLDR or Key Takeaways section which should be ideally on the top section of the page, right after the contributor-hero.

[xames3]

• In my initial investigation, I realized that rendering the TLDR/Summary in a list-table style format was not appropriate and seemed misleading to the context.
• When experimented with different variations like normal unordered list and list with referenced header sections, it didn't work out very well with initial users.
• Hence opting for simple dropdown style collapsible view which can be expanded upon by the user themselves if they're interested in it. The view is rendered as a simple unordered list with strong title/caption followed by the summarized context.