Using a webhook for the Reddit post relay

[SebastiaanZ]

We're currently relaying the new Reddit posts (and the weekly top posts overview) as regular messages to a text channel. Since the subreddit sees frequent activity, I propose to change this to a method that uses a webhook to post the messages to the channel.

This has two advantages:

1. Webhooks use a different rate limit pool than regular messages;
2. We can use a stylized author icon and display_name

The latter is not really important, but will look nice; the former is the biggest advantage of this change.

This should not be difficult to implement, although an admin+ needs to create the proper webhook for the relevant channel.

[mathsman5133]

I could work on this.

I also believe the auto posters could utilise discord.ext.tasks extension for cleanness of code, and to resolve issues such as #360/#361

[lemonsaurus]

@mathsman5133 you could work on this or you are going to work on this? it's yours if you want it.

If you're doing this, I have one more request for this cog, which came up in the last staff meeting. Instead of relaying every post that is posted on /r/python, it would be nice if it just posted the top 3 posts that day, once every day. Currently, the channel is very noisy and I doubt anyone really uses it for anything except the weekly top 3 in the pins.

[mathsman5133]

I will work on this, please :)

The weekly is currently top 5 - just making sure you want the daily to be top 3? Also, is there a specific time every day - and/or do you want to make this configurable?

Also, just to confirm - although /r/python is the only subreddit being tracked now, any future subreddits will just have daily/weekly posts, too - in other words I can scrap the auto new poster?