docs(contributing): update commands for building TA

[vtsvetkov-splunk]

Issue number: -

Summary

Changes

Update syntactically incorrect commands in docs

User experience

Enjoyable experience while building TAs with local version of UCC

Checklist

If your change doesn't seem to apply, please leave them unchecked.

• [x] I have performed a self-review of this change
• [ ] Changes have been tested
• [x] Changes are documented
• [x] PR title follows conventional commit semantics