Fix Pip's window

[rogers492]

• [ ] Get wood filler and rot hardener
• [ ] Remove window
• [ ] Remove loose rot and harden frame
• [ ] Apply filler layer 1
• [ ] Apply filler layer 2
• [ ] Apply filler layer 3
• [ ] Refit window

[rogers492]

Change of plan: getting the 3 upstairs windows replaced by UPVC from Dartmoor Windows.

[rogers492]

Closed - dealt with by #246