Review the hello world series for consistency

[SimiHunjan]

Review the hello world series for consistency and validate the basic topics for a developer to get started in the Hedera ecosystem are covered.

[SimiHunjan]

Feedback:

• Should we have a readme at each directory level to explain the contents in the directory or will the root readme be enough since it is the same example duplicated by language?
• I don't think we need the "00. 01. etc" numbering because these don't have to be done in order
• The titles for the examples should match the name of the getting started example. For example, hfs-files should be create-a-file and ScriptsHfs.java should be create-a-file. Makes it easy for someone to follow along vs. having different titles reference the same task.