Modification to software source code schema

[Castronova]

Below are comments from an outstanding PR on software source code. Moving these to an issue so we can merge the PR and consolidate repositories.

1. Consider changing to something like the following:

To classify a record as a computer programming source code, "@type: "SoftwareSourceCode" should be used in the json schema. This will classify the record such as compile ready solutions, code snippet samples, scripts, etc. as a specific Schema.Org type called SoftwareSourceCode for which the metadata should be described using the core metadata, as well as the software-source-code-specific properties for the Schema:SoftwareSourceCode class. The following table outlines the required and optional properties selected from Schema.Org vocabulary to design the I-GUIDE software source code metadata schema. These properties are encoded as 1 or 1+ for required and 0,1 or 0+ for optional in the Cardinality column of the table below.

to

To classify a record as a computer programming source code, use "@type: "SoftwareSourceCode" in the json schema. This is appropriate for records including code snippet samples, scripts, notebooks, etc. The following table outlines the required and optional properties to sufficiently describe software source code objects. Required properties have a cardinality of 1 or 1+ and optional properties have a cardinalities of 0, 0+, 1.

2. I'm not sure that we want to embed source code within the schema. I wonder if this could have security implications. See:

| [text](https://schema.org/text) | CreativeWork | Text | 0,1 | The textual content of the source code. |