Version 2.1 and initial playtesting

Changes

• changed formula for max Flow
• allow expending Stress and Harm for Flow
• add Energy Drain ability

Have been lucky enough to get one of my players to playtest this.

Initial thoughts

• maximum Flow feels restrictive. Addressed this in latest update
• the formula and subsystem for Flow is a bit complex. Still thinking about how to handle this.
• might end up taking over the roles of other PCs. I think this is quite in line with how a Wizard should feel.