Merge #1637

1637: updated recurrence.md which fixes #1564 r=CarloLucibello a=aditkumar72

changed `rand` and `randn` definition to `rand(Float32, ...)` and `randn(Float32, ...)`

Co-authored-by: Aditya Tewary <aditkumar72@gmail.com>

Author: bors[bot]

docs/src/models/recurrence.md

@@ -13,19 +13,19 @@ An aspect to recognize is that in such model, the recurrent cells `A` all refer
 In the most basic RNN case, cell A could be defined by the following: 
 
 ```julia
-Wxh = randn(5, 2)
-Whh = randn(5, 5)
-b   = randn(5)
+Wxh = randn(Float32, 5, 2)
+Whh = randn(Float32, 5, 5)
+b   = randn(Float32, 5)
 
-function rnn(h, x)
-  h = tanh.(Wxh * x .+ Whh * h .+ b)
-  return h, h
+function rnn_cell(h, x)
+    h = tanh.(Wxh * x .+ Whh * h .+ b)
+    return h, h
 end
 
-x = rand(2) # dummy data
-h = rand(5)  # initial hidden state
+x = rand(Float32, 2) # dummy data
+h = rand(Float32, 5)  # initial hidden state
 
-h, y = rnn(h, x)
+h, y = rnn_cell(h, x)
 ```
 
 Notice how the above is essentially a `Dense` layer that acts on two inputs, `h` and `x`.