docs: Remove TOC in UT advice doc
Remove the table of contents in the Unit Test Advice document since
GitHub auto-generates these now.
See:
# Unit Test Advice
-* [Overview](#overview)
-* [Assertions](#assertions)
- * [golang assertions](#golang-assertions)
- * [rust assertions](#rust-assertions)
-* [Table driven tests](#table-driven-tests)
- * [golang table driven tests](#golang-table-driven-tests)
- * [rust table driven tests](#rust-table-driven-tests)
-* [Temporary files](#temporary-files)
- * [golang temporary files](#golang-temporary-files)
- * [rust temporary files](#rust-temporary-files)
-* [User running the test](#user-running-the-test)
- * [running golang tests as different users](#running-golang-tests-as-different-users)
- * [running rust tests as different users](#running-rust-tests-as-different-users)
-
## Overview
This document offers advice on writing a Unit Test (UT) in
