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>

config.yml

@@ -32,6 +32,10 @@ index.meili.host:
 # Set the API key for the Meiliseach server
 index.meili.api-key:
 
+# Set the default search fields. Can contain multiple fields (e.g., `content,username`).
+# Fields: content,user,title,description,filename,extension,language,topic. Default: content
+search.default: content
+
 # Default branch name used by Opengist when initializing Git repositories.
 # If not set, uses the Git default branch name. See https://git-scm.com/book/en/v2/Getting-Started-First-Time-Git-Setup#_new_default_branch
 git.default-branch: