The first_team tag can be used to indicate that a team is a 'reserve
team'. The value for this new tag is the name of the first team
for this reserve team. The reserve_level is used to indicate if this
is the 2nd, 3rd, 4th, etc. team for the first team. For example:
<team>
<team_name>Blue</team_name>
</team>
<team>
<team_name>Blue 2</team_name>
<first_team>Blue</first_team>
<reserve_level>2</reserve_level>
</team>
<team>
<team_name>Blue 3</team_name>
<first_team>Blue</first_team>
<reserve_level>3</reserve_level>
</team>