🛠 add explicit return types here and there

[codecov[bot]]

Codecov Report

Merging #305 into master will not change coverage. The diff coverage is 100%.

Impacted Files	Coverage Δ
packages/codecov-lite/src/getConfig.ts	100% <ø> (ø)	:arrow_up:
packages/start/plugin/src/index.ts	100% <ø> (ø)	:arrow_up:
packages/dleet/src/index.ts	100% <100%> (ø)	:arrow_up:
packages/spyfn/src/index.ts	100% <100%> (ø)	:arrow_up:
packages/rplace/src/index.ts	100% <100%> (ø)	:arrow_up:
packages/codecov-lite/src/index.ts	92.3% <100%> (ø)	:arrow_up:
packages/ekst/src/index.ts	100% <100%> (ø)	:arrow_up: