Write new timeline loading blocked notice

src/site/api/routes.js

@@ -160,15 +160,7 @@ module.exports = [
 						withInstancesLink: false
 					})
 				} else if (error === constants.symbols.INSTAGRAM_DEMANDS_LOGIN || error === constants.symbols.RATE_LIMITED) {
-					return render(503, "pug/friendlyerror.pug", {
-						statusCode: 503,
-						title: "Timeline loading blocked",
-						message: "Timeline loading blocked",
-						explanation:
-								"Instagram blocked this server for requesting too many timeline pages."
-							+"\nThis block is not permanent, and will expire soon."
-							+"\nPlease wait a few minutes before trying again."
-					})
+					return render(503, "pug/fragments/timeline_loading_blocked.pug")
 				} else {
 					throw error
 				}

src/site/pug/fragments/timeline_loading_blocked.pug

@@ -0,0 +1,7 @@
+.error-fragment
+	.message Timeline loading blocked
+	.explanation.
+		Instagram blocked this server for requesting too many timeline pages.
+		This block is not permanent, and will expire soon.
+		Please wait a few minutes before trying again.
+		Or, you could try #[a(href="https://git.sr.ht/~cadence/bibliogram-docs/tree/master/docs/Instances.md") browsing Bibliogram on another instance.]

src/site/sass/includes/_main.sass

@@ -534,6 +534,19 @@ body
 		&:target
 			display: block
 
+.error-fragment
+	text-align: center
+	padding: 30px 10px
+
+	.message
+		font-size: 32px
+		margin-bottom: 10px
+
+	.explanation
+		font-size: 20px
+		white-space: pre-line
+		line-height: 1.3
+
 .homepage
 	display: flex
 	flex-direction: column