docs: add types to tracers (1/3)

[bonjourmauko]

Depends on #1279
Part of #1245

Documentation

• Add types to common tracers (SimpleTracer, FlatTracer, etc.)

[coveralls]

coverage: 82.734% (+0.5%) from 82.273%
when pulling 4e029f5 on docs/add-types-to-simple-tracer
into 5a131cf on master.

[coveralls]

coverage: 82.734% (+0.5%) from 82.273%
when pulling 4e029f5 on docs/add-types-to-simple-tracer
into 5a131cf on master.

[coveralls]

coverage: 82.734% (+0.5%) from 82.273%
when pulling 4e029f5 on docs/add-types-to-simple-tracer
into 5a131cf on master.

[coveralls]

coverage: 82.734% (+0.5%) from 82.273%
when pulling 4e029f5 on docs/add-types-to-simple-tracer
into 5a131cf on master.

[coveralls]

coverage: 82.734% (+0.5%) from 82.273%
when pulling 4e029f5 on docs/add-types-to-simple-tracer
into 5a131cf on master.

[bonjourmauko]

coverage: 82.734% (+0.5%) from 82.273% when pulling 4e029f5 on docs/add-types-to-simple-tracer into 5a131cf on master.

Bye!