Display the resource topic when using the `!resources` command

[n0Oo0Oo0b]

The !resources command accepts an optional argument to specify the resource topic in the URL. For example, !resources data science will result in the following link: https://www.pythondiscord.com/resources/?topics=data-science

However, there is no difference in the embed (other than the hyperlink itself) to indicate that a topic has been specified. I propose that when a topic is specified, it will be added to the title of the embed, like "Resources for: Data science".

(I would like to implement this myself)

[hedyhli]

Ideally, we would want to check for the command arguments against the list of valid filters (see the above linked issue - or python-discord/site#710). So once we have that endpoint on the site, we can then add in the "Resources for: " if the argument is a valid topic, and just the current normal "Resources" title otherwise.