Standardize headers in docstrings

Author: juliohm

src/rand.jl

@@ -8,7 +8,7 @@
 Generate a random geometry of type `G` with CRS `crs`,
 optionally passing a random number generator `rng`.
 
-# Examples
+## Examples
 
 ```julia
 rand(Point)
@@ -26,7 +26,7 @@ Random.rand(rng::Random.AbstractRNG, G::Type{<:Geometry}; crs=Cartesian3D) = _ra
 Generate a vector of `n` random geometries of type `G` with CRS `crs`,
 optionally passing a random number generator `rng`.
 
-# Examples
+## Examples
 
 ```julia
 rand(Point, 10)

src/transforms/affine.jl

@@ -7,7 +7,7 @@
 
 Affine transform `Ax + b` with matrix `A` and vector `b`.
 
-# Examples
+## Examples
 
 ```julia
 Affine(AngleAxis(0.2, 1.0, 0.0, 0.0), [-2, 2, 2])