Adding namespace qualifiers in documentation

Description

README.md has code examples that are missing namespace qualifiers, Adding them will make it easy to copy the code in REPL and make it work.
In addition to that there are couple of fixes for misspelled words.
The commit is in the following fork for reference

https://raw.githubusercontent.com/as17237/data.csv/master/README.md

Environment

None

Assignee

Jonas Enlund

Reporter

import

Labels

Approval

None

Patch

None

Priority

Minor
Configure