Add documentation to every function and automatic doc html building (#6)

Reviewed-on: Rubydragon/MetagraphOptimization.jl#6
Co-authored-by: Anton Reinhard <anton.reinhard@proton.me>
Co-committed-by: Anton Reinhard <anton.reinhard@proton.me>

src/task/compare.jl

@@ -1,11 +1,26 @@
+"""
+    ==(t1::AbstractTask, t2::AbstractTask)
+
+Fallback implementation of equality comparison between two abstract tasks. Always returns false. For equal specific types of t1 and t2, a more specific comparison is called instead, doing an actual comparison.
+"""
 function ==(t1::AbstractTask, t2::AbstractTask)
     return false
 end
 
+"""
+    ==(t1::AbstractComputeTask, t2::AbstractComputeTask)
+
+Equality comparison between two compute tasks.
+"""
 function ==(t1::AbstractComputeTask, t2::AbstractComputeTask)
     return typeof(t1) == typeof(t2)
 end
 
+"""
+    ==(t1::AbstractDataTask, t2::AbstractDataTask)
+
+Equality comparison between two data tasks.
+"""
 function ==(t1::AbstractDataTask, t2::AbstractDataTask)
     return data(t1) == data(t2)
 end