Add a shameless promotion of Yarn.social in all feeds preamble

Makefile

@@ -1,8 +1,8 @@
 .PHONY: dev build install image test release clean
 
+VERSION=$(shell git describe --abbrev=0 --tags 2>/dev/null || echo "$VERSION")
+COMMIT=$(shell git rev-parse --short HEAD || echo "$COMMIT")
 CGO_ENABLED=0
-VERSION=$(shell git describe --abbrev=0 --tags)
-COMMIT=$(shell git rev-parse --short HEAD)
 
 all: dev
 

handlers.go

@@ -185,6 +185,8 @@ func (app *App) FeedHandler(w http.ResponseWriter, r *http.Request) {
 			"Avatar":       feed.Avatar,
 			"Description":  feed.Description,
 			"LastModified": fileInfo.ModTime().UTC().Format(time.RFC3339),
+
+			"SoftwareVersion": FullVersion(),
 		}
 
 		preamble, err := RenderPlainText(preambleTemplate, ctx)

templates.go

@@ -23,6 +23,9 @@ const preambleTemplate = `# Twtxt is an open, distributed microblogging platform
 #
 # Learn more about twtxt at  https://github.com/buckket/twtxt
 #
+# This is an automated Yarn.social feed running feeds v{{ .SoftwareVersion }}
+# Learn more about Yarn.social at https://yarn.social
+#
 # nick        = {{ .Name }}
 # url         = {{ .URL }}
 # source      = {{ .Source }}