Option to mitigate rate limits

[nesges]

I fetch a lot (>300) of hashtags with GMF which leads to 429 (Too Many Requests) errors on most Mastodon servers:

Error fetching tag traveller from sueden.social, status code: TooManyRequests. Error: Response status code does not indicate success: 429 (Too Many Requests).

The Mastodon API has a default limit of 300 requests per 5 minutes (https://docs.joinmastodon.org/api/rate-limits/). Please add an option to make GMF pause for X seconds every Y tags (e.g. pause 60 seconds after 50 tags, 300 seconds after 300 tags or 1 seconds after 1 tag etc.)