clarify that msDesc can be used for all text bearing objects including (early) printed books

[holfordm]

this is in response to discussion on the mailing list:
https://listserv.brown.edu/archives/cgi-bin/wa?A1=ind1810&L=TEI-L#11
The discussion / decisions mentioned in the final message in this thread (https://listserv.brown.edu/archives/cgi-bin/wa?A2=ind1810&L=TEI-L&D=0&P=72748) are not, I think, currenlty captured in the guidelines

[ebeshero]

@holfordm Thanks for this! We may want to address this together with #1832

[ebeshero]

F2F: Council points out passages in Ch. 10 to make plainer that manuscripts can apply broadly to printed primary sources. We should add examples to show a broad range of use cases.

[emylonas]

• add text to Tagdoc - "(manuscript description) contains a description of a single identifiable manuscript or other text-bearing object" so that it becomes "(manuscript description) contains a description of a single identifiable manuscript or other text-bearing object such as early printed books, fascicles ... "
• in the MS chapter: improve 1st para to be inclusive of text bearing objects that aren't manuscripts
• Eyeball the rest of the chapter for language that refers to manuscripts and expand it to other printed objects.
• Add a reference to object and explain what it's best suited to