feat: search all fields (#622)

* ✨ feat(search): search all feature

- add Description field to Gist struct and index it
- extend SearchGistMetadata with Description and Content
- update Bleve and Meilisearch to index and search Description
- modify ParseSearchQueryStr to parse description: and content: keywords
- update templates and i18n for new search options

* Fix test

* Set content by default

Signed-off-by: Thomas Miceli <tho.miceli@gmail.com>

* Config to define default searchable fields

Signed-off-by: Thomas Miceli <tho.miceli@gmail.com>

---------

Signed-off-by: Thomas Miceli <tho.miceli@gmail.com>
Co-authored-by: Thomas Miceli <tho.miceli@gmail.com>

internal/web/server/renderer.go

@@ -147,7 +147,10 @@ func (s *Server) setFuncMap() {
 			return dict, nil
 		},
 		"addMetadataToSearchQuery": func(input, key, value string) string {
-			content, metadata := handlers.ParseSearchQueryStr(input)
+			metadata := handlers.ParseSearchQueryStr(input)
+			// extract free-text content (stored under "all") and remove it from metadata
+			content := metadata["all"]
+			delete(metadata, "all")
 
 			metadata[key] = value