go get wrong module path in README.md

[jefvantongerloo]

Current command:
go get github.com/Microsoft/ethr

Output:

go get: github.com/Microsoft/[email protected] updating to
	github.com/Microsoft/[email protected]: parsing go.mod:
	module declares its path as: github.com/microsoft/ethr
	        but was required as: github.com/Microsoft/ethr

Fixed command:
go get github.com/microsoft/ethr

Output:

go: downloading github.com/microsoft/ethr v1.0.0
go: downloading github.com/mattn/go-runewidth v0.0.9
go: downloading golang.org/x/sys v0.0.0-20200918174421-af09f7315aff
go: downloading github.com/nsf/termbox-go v0.0.0-20200418040025-38ba6e5628f1
go: downloading golang.org/x/net v0.0.0-20210331060903-cb1fcc7394e5
go: downloading golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44

Make sure to clean cache when module is already downloaded:
go clean -modcache

[jefvantongerloo]

Fixed in PR #148