Fix Poisson example (#828)

jishnub · web-flow · commit 8bad4d27251c · 2022-09-26T11:02:33.000+04:00
diff --git a/examples/PDE_Poisson.jl b/examples/PDE_Poisson.jl
@@ -2,7 +2,7 @@
 
 # We solve the Poisson equation
 # ```math
-# Δu(x,y) = 0
+# Δu(x,y) = f(x,y)
 # ```
 # on the rectangle `-1..1 × -1..1`,
 # with zero boundary conditions:
