Errors in README

[jlous]

I finally got the bindings to work in my kotlin project, after finding and fixing these problems:

• The example bindings use the "jaxb" prefix but don't define it.
  • either remove all jaxb: prefixes, or add xmlns="https://jakarta.ee/xml/ns/jaxb"
• There are duplicate bindings for the same xs:-tags
  • this is probably intentional to illustrate alteratives, but in any case:
  • remove all but on of each
• There is no such thing as java.time.OffsetDate
  • remove the offending line
• The text says "src/main/bindings/bindings.xml" but the xjc config implies "src/main/xjb/bindings.xjb"
  • choose one and harmonise the other
• Xml editor complains that "extensionBindingPrefixes" "is not allowed here", whether it is prefixed or not
  • removing the whole attribute seems to work fine
• bindings need to be under the java source root, so in a kotlin project:
  • add src/main/java and move bindings somewhere in there
  • adjust xjc config accordingly