key: ignore empty values in `ValueWithShadows` (go-ini#316)

Return an empty array from `ValueWithShadows` if there is none (go-in…

…i#313)

Co-authored-by: Joe Chen <[email protected]>

Fix nested values can span sections (go-ini#306)

Fix python multiline EOF error (go-ini#309)

file: add `HasSection` method (go-ini#308)

Co-authored-by: Joe Chen <[email protected]>

Fix parsing python multiline string (go-ini#299)

file: fix legacy tests

test: rename package to be same as the main (go-ini#304)

ci: workaround to make lint work (go-ini#303)

key: add `AllowDuplicateShadowValues` option (go-ini#298)