[feature] Add opt-in RSS feed for account's latest Public posts (#897)

* start adding rss functionality

* add gorilla/feeds dependency

* first bash at building rss feed
still needs work, this is an interim commit

* tidy up a bit

* add publicOnly option to GetAccountLastPosted

* implement rss endpoint

* fix test

* add initial user docs for rss

* update rss logo

* docs update

* add rssFeed to frontend

* feed -> feed.rss

* enableRSS

* increase rss logo size a lil bit

* add rss toggle

* move emojify to text package

* fiddle with rss feed formatting

* add Text field to test statuses

* move status to rss item to typeconverter

* update bun schema for enablerss

* simplify 304 checking

* assume account not rss

* update tests

* update swagger docs

* allow more characters in title, trim nicer

* update last posted to be more consistent

internal/api/model/account.go

@@ -92,6 +92,8 @@ type Account struct {
 	Source *Source `json:"source,omitempty"`
 	// CustomCSS to include when rendering this account's profile or statuses.
 	CustomCSS string `json:"custom_css,omitempty"`
+	// Account has enabled RSS feed.
+	EnableRSS bool `json:"enable_rss,omitempty"`
 }
 
 // AccountCreateRequest models account creation parameters.
@@ -155,6 +157,8 @@ type UpdateCredentialsRequest struct {
 	FieldsAttributes *[]UpdateField `form:"fields_attributes" json:"fields_attributes" xml:"fields_attributes"`
 	// Custom CSS to be included when rendering this account's profile or statuses.
 	CustomCSS *string `form:"custom_css" json:"custom_css" xml:"custom_css"`
+	// Enable RSS feed of public toots for this account at /@[username]/feed.rss
+	EnableRSS *bool `form:"enable_rss" json:"enable_rss" xml:"enable_rss"`
 }
 
 // UpdateSource is to be used specifically in an UpdateCredentialsRequest.