Add registration link to JuMP-dev (#127)

Author: odow

_posts/2023-10-22-jump_dev_2024.md

@@ -19,14 +19,24 @@ aspects of [JuMP](https://github.com/jump-dev/JuMP.jl) and related packages. In
 particular, we invite new contributors and those who have not met the core
 development team.
 
+All participants will uphold the [JuMP Code of Conduct](https://github.com/jump-dev/JuMP.jl/blob/master/CODE_OF_CONDUCT.md).
+
 ## How do I attend?
 
-To attend JuMP-dev, you must purchase a ticket. Ticket sales will open in early 2024.
-Accepted speakers at JuMP-dev will receive a free ticket.
+To attend JuMP-dev, you must register and purchase a ticket:
 
-You do not need a ticket to ISMP to attend JuMP-dev.
+[https://symposia.gerad.ca/JumpDev-2024/register](https://symposia.gerad.ca/JumpDev-2024/register)
 
-All participants will uphold the [JuMP Code of Conduct](https://github.com/jump-dev/JuMP.jl/blob/master/CODE_OF_CONDUCT.md).
+The cost of a ticket before June 19 is CAD50. After June 19, the price will
+rise to CAD75.
+
+If you are a student and the cost is prohibitive to you attending, please email
+`[email protected]`.
+
+If you are an accepted speaker, we will email you with a discount code to register
+a free ticket.
+
+You do not need a ticket to ISMP to attend JuMP-dev.
 
 ## Venue