Included sample and extension .ML extension for Standard ML files

[akissinger]

Standard ML code (particularly the Poly/ML dialect) often has the .ML file extension. Probably the most prevalent example is in the theorem prover Isabelle. See:

• http://isabelle.in.tum.de/repos/isabelle/file/1d122af2b11a/src/Pure

Examples on github:

• Quantomatic/quantomatic
• Quantomatic/isaplib
• ggrov/psgraph

[pchaigno]

Is the file extension .ML always in uppercase normally?
In ggrov/psgraph, there is a file which is still recognized as OCaml because his extension is lowercase.

[akissinger]

I've only ever encountered upper-case "ML" or lower-case "sml" as extensions. The one file in the psgraph repo seems to be a throwaway.

[pchaigno]

Ok, in that case, all's good! :)