Add mention of closing date

sites/main-site/src/content/events/2025/hackathon-march-2025/index.mdx

@@ -51,10 +51,10 @@ Any space will do: be it a meeting room for 5-10 people through to larger spaces
 
 The steps to host a site are:
 
-1. Fill in the local site registraion form below
-2. Coordinate with the hackathon organisers to create a site-specific webpage on this website
-3. Advertise - both locally and online
-4. During the event: act as a contact point with the hackathon organisers
+1. ✍️ Fill in the local site registraion form below
+2. 👩🏻‍💻 Coordinate with the hackathon organisers to create a site-specific webpage on this website
+3. 📢 Advertise - both locally and online
+4. ☎️ During the event: act as a contact point with the hackathon organisers
 
 For more details, see the [About nf-core hackathons](https://youtu.be/nmp0pXL7GqQ?si=QShy0tqljhgap3lV&t=220)
 bytesize talk:
@@ -70,10 +70,14 @@ bytesize talk:
     </div>
 </div>
 
-In previous years, Seqera has sponsored pizza.
+:pizza: In previous years, Seqera has sponsored pizza.
 We're not yet sure how much funding will be available in 2025 or what shape it will take,
 so please don't plan around this.
 
+:calendar: There is no closing date for local site registration, however the sooner you register your interest the better.
+We use the site names in the main registration form and it really helps with planning.
+Also if we know about your site we'll have more time to help advertise and get folks to join!
+
 If you have any questions, jump into the [`#hackathon-mar-2025` channel](https://nfcore.slack.com/archives/C081XQ6T3M4)
 on the [nf-core Slack](https://nf-co.re/join#slack) and we'll be happy to help.