Document how to associate name of NXDL with requirements in the XML file.

[prjemian]

The manual must make clear how to properly construct an NXDL file that connects the NXDL file name with the definition@name=".." attribute in the top-most element and the required enumeration element in the definition field below. This same name (and spelling, and upper/lower case representation) should match the file name. Consider putting this into the manual as a sidebar.

And, any content referenced by the NXDL (such as images) be placed in a subdirectory with the name chosen by stripping off the NX. (as in: NXDL for NXthing would be in file NXthing.nxdl.xml)

file: NXthing.nxdl.xml
resources: thing/image1.png

In the NXDL file:

<definition name="NXthing" ... />

<!-- later -->

        <field name="definition">
            <doc>Official NeXus NXDL schema to which this file conforms.</doc>
            <enumeration>
                <item value="NXthing"/>                
            </enumeration>
        </field>

Originally posted by @prjemian in #910 (comment)

[prjemian]

@RussBerg Didn't you work on a PR similar to this issue?

[prjemian]

PR #1089 and issue #1001

[prjemian]

Looks like additional work, advising how to create an NXDL file.

[benajamin]

I was just looking at it and thinking about picking it up.

[prjemian]

@benajamin #1046 is related