Comment out decapode UWD preview (for now)

[brandomr]

Since there are issues with string escapes in Decapodes UWD previews cannot be consistently generated. This is a known bug in Decapodes that we expect TA2 to address; until then we should comment out this line.

As a workaround Terarium could generate its own UWD via the JSON from the preview. FYI @mwdchang @YohannParis

@fivegrant let's also remove that extraneous decapodes context file

Note: @pascaleproulx once this is completed Beaker will support Decapode composition: load 2 decapode AMRs, compose them together, and store the result. This satisfies a very minimal thin thread and resolves #25

[brandomr]

@pascaleproulx writing a decapode in decapod syntax and saving it as an AMR within beaker is already supported. The syntax would look something like:

glens_law = @decapode begin
  Γ::Form1
  (A,ρ,g,n)::Constant

  Γ == (2/(n+2))*A*(ρ*g)^n
end

In other words, we can support the Grigoriev Ice Cap example minus the UWD visualization, though I suspect it would be better to have a web-interactive visualization of this from the JSON anyway.