Updated commands in Classpath Example that were outdated

[Amemeda]

updated classpath.md,

• removed first 3 commands along with their text instructions
• root@uno examples.nofoo> config -t examples.nofoo -s table.class.loader.context=cx1 was updated to use file path instead of cx1 in 2 locations

[Amemeda]

Please let me know if the edited text instructions at the beginning match/make sense with the updated commands