fix: remove empty line before End Waypoint marker

[piotrnajda3000]

Anytime a waypoint is inserted, it looks like this:

%% Begin Waypoint %%
- Some file
- Some other file

%% End Waypoint %%

Notice the empty line.

If you manually remove it:

%% Begin Waypoint %%
- Some file
- Some other file
%% End Waypoint %%

it gets added back in after a file gets added.

%% Begin Waypoint %%
- Some file
- Some other file
- New file

%% End Waypoint %%