Issues in MetaData example

[martinweismann]

The Metadata example https://github.com/3MFConsortium/spec_core/blob/master/3MF%20Core%20Specification.md#appendix-b2-3mf-metadata-example has two issues:

• The copyright symbol is not correctly displayed
• <metadata name="ChangeHistory">2013-10-07 Initial model</metadata> : ChangeHistory is not a "well-known" name according to Table 3-1.

[martinweismann]

not an issue