Create a `docs/parameter_record` dir

[onkoe]

a solution: create a docs/parameter_record/PARAMETER_RECORD.md for each testing day. document our changes to nav2.yaml and explain what happened and why

Originally posted by @onkoe in #167 (comment)

[onkoe]

template idea:

# Parameter Record

## 20yy-mm-dd

### Change 1: Reasoning

We changed (...) because (...). Blah blah blah.

### Changes (`diff`)

```diff
(...)
```

### Result

The Rover exploded and we had to buy a new GPS again :)

[onkoe]

maybe have a docs/parameter_record/README.md that describes how to make parameter changes and how to add them to this record

[logbasem]

Theoretically, we don't have to have it just be just nav2-- could also be something like

• NAV2_PARAMS_RECORD.md
• LIDAR_PARAMS_RECORD.md
• etc.

(But probably focus on NAV2_ PARAMS_RECORD.md for now)