Replace suggestion of using `systemctl edit`

Editing `ExecStart=` with `systemctl edit` did
not work for me. Running
`systemctl restart thermald.service` afterwards
was giving errors every time with reason "Unit
thermald.service has a bad unit file setting".

By running `systemctl status thermald.service`,
I was reading this error:

    redis.service has more than one ExecStart=
    setting, which is only allowed for
    Type=oneshot services. Refusing.

By looking through the Internet for answers,
I found a suggestion from a user saying that
"The `ExecStart=` line cannot be modified with
`systemctl edit`"
(https://unix.stackexchange.com/questions/409354).

What worked was replacing the thermald.service file
directly to `/etc/systemd/system/` and
`/usr/lib/systemd/system` worked, as suggested
in the README.md present in the folder containing
example configurations for Surface Pro 5 from
this repository.

contrib/thermald/README.md

@@ -14,4 +14,4 @@ Both XML files (`thermal-conf.xml` and `thermal-cpu-cdev-order-xml`) need to be
 
 Newer thermald versions attempt to automatically load the configuration from ACPI.
 If you want to use a manual configuration with such a version, you may need to remove the `--adaptive` option from the systemd service `ExecStart` line.
-You can do so by running `sudo systemctl edit thermald.service`.
+You can do so by overwriting `thermald.service`. This file is present in `/lib/systemd/system/` (it may also be in `/usr/lib/systemd/system/`).