edits; simplify caching

CwJ/alternatives/symbolics.__jmd__

@@ -1,5 +1,39 @@
 # Symbolics.jl
 
+Incorporate:
+
+Basics
+
+
+https://github.com/SciML/ModelingToolkit.jl
+https://github.com/JuliaSymbolics/Symbolics.jl
+https://github.com/JuliaSymbolics/SymbolicUtils.jl
+
+* Rewriting
+
+https://github.com/JuliaSymbolics/SymbolicUtils.jl
+
+* Plotting
+
+Polynomials
+
+
+Limits
+
+XXX ... room here!
+
+Derivatives
+
+https://github.com/JuliaSymbolics/Symbolics.jl
+
+
+Integration
+
+https://github.com/SciML/SymbolicNumericIntegration.jl
+
+
+
+
 The `Symbolics.jl` package is a Computer Algebra System (CAS) built entirely in `Julia`.
 This package is under heavy development.