Add to KOReader

[shuvashish76]

Request to add StarDict dictionary to KOReader dictionaries.lua via PR so that users can directly download from the built in UI. Also add other dictionaries as well.

info about KOReader's dictionary support: https://github.com/koreader/koreader/wiki/Dictionary-support

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• Add installation instruction for KOReader https://digitalpalidictionary.github.io/install/
• Add to integration list https://digitalpalidictionary.github.io/integrations/