[feature request] Display frequency ranks for words

[denyeo]

(This one's a nice-to-have)
One thing I miss from Rikaisama is the frequency rank that it can output for each word. This helps me decide whether I should export the definition to Anki (I tend not to export uncommon words). Maybe Yomichan could potentially consider displaying this in the future, though the work might be slightly involved. Rikaisama uses the 5,000+ novel (Innocent?) corpus, while Aedict3 uses the Kamermans and Matsushita frequency lists.

Yomichan already displays frequency tags like P, news, ichi, etc. Those are useful and I always export words with those tags to Anki. But most words don't have them, so having specific frequency ranks would be helpful for more advanced learners. For example, I now add words from Aedict3 when they're in the top 20,000 by Matsushita rank.

[FooSoft]

Fixed