chore: add standard devenv.nix #5

.../mod/cache/download/github.com/pmezard/go-difflib/@v/list

...che/download/github.com/pmezard/go-difflib/@v/v1.0.0.info

...che/download/github.com/pmezard/go-difflib/@v/v1.0.0.lock

...ache/download/github.com/pmezard/go-difflib/@v/v1.0.0.mod

...ache/download/github.com/pmezard/go-difflib/@v/v1.0.0.zip

.../download/github.com/pmezard/go-difflib/@v/v1.0.0.ziphash

...o/pkg/mod/cache/download/github.com/stretchr/objx/@v/list

...mod/cache/download/github.com/stretchr/objx/@v/v0.1.0.mod

...mod/cache/download/github.com/stretchr/objx/@v/v0.4.0.mod

...mod/cache/download/github.com/stretchr/objx/@v/v0.5.0.mod

...kg/mod/cache/download/github.com/stretchr/testify/@v/list

.../cache/download/github.com/stretchr/testify/@v/v1.7.1.mod

.../cache/download/github.com/stretchr/testify/@v/v1.8.0.mod

...cache/download/github.com/stretchr/testify/@v/v1.8.2.info

...cache/download/github.com/stretchr/testify/@v/v1.8.2.lock

.../cache/download/github.com/stretchr/testify/@v/v1.8.2.mod

.../cache/download/github.com/stretchr/testify/@v/v1.8.2.zip

...he/download/github.com/stretchr/testify/@v/v1.8.2.ziphash

...schukai.com/oss/libraries/go/utilities/pathfinder/@v/list

....com/oss/libraries/go/utilities/pathfinder/@v/v0.5.2.lock