Fixes #5611: Modified upgrading techniques section so new techniques are...

... added as well
We already cd'ed into this directory (well actually, into techniques, which is more appropriate since some users have that as a sub-git repo) above. I think here is the right place to do it, but we should adjust the procedure above since it is more commands that necessary. Can you replace:

```
 cd /var/rudder/configuration-repository/techniques
 cp -a /opt/rudder/share/techniques/* .
```

with:

```
cp -a /opt/rudder/share/techniques/* /var/rudder/configuration-repository/techniques/
```

?