readme: demonstrate new custom fields in example config.

Closes #184

Author: jtagcat

README.md

@@ -79,7 +79,7 @@ vimeo = [ # Multiple keys will be rotated.
   quality = "high" # or "low"
   format = "video" # or "audio"
   # custom.cover_art_quality use "high" or "low" to special cover image quality from channel cover default is equal with "quality" and disable when custom.cover_art was set.
-  # custom = { cover_art = "{IMAGE_URL}}", cover_art_quality = "high", category = "TV", subcategories = ["Documentary", "Tech News"], explicit = true, lang = "en" } # Optional feed customizations
+  # custom = { title = "Level1News", description = "News sections of Level1Techs, in a podcast feed!", author = "Level1Tech", cover_art = "{IMAGE_URL}", cover_art_quality = "high", category = "TV", subcategories = ["Documentary", "Tech News"], explicit = true, lang = "en" } # Optional feed customizations
   # max_height = 720 # Optional maximal height of video, example: 720, 1080, 1440, 2160, ...
   # cron_schedule = "@every 12h" # Optional cron expression format. If set then overwrite 'update_period'. See details below
   # filters = { title = "regex for title here", not_title = "regex for negative title match", description = "...", not_description = "..." } # Optional Golang regexp format. If set, then only download matching episodes.