Fix typos discovered by codespell

[cclauss]

Fix typos discovered by codespell - https://github.com/codespell-project/codespell

% codespell --ignore-words-list=intoto,nd,vertexes --skip="*.sum"

./README.md:246: Shortand ==> Shorthand
./README.md:489: defails ==> details, derails
./pkg/cmd/registry/registry.go:394: specificies ==> specifics, specifies
./pkg/buildx/bake/hclparser/gohcl/encode.go:37: togather ==> together, to gather
./pkg/buildx/bake/hclparser/gohcl/schema.go:56: absense ==> absence
./pkg/buildx/commands/build.go:822: Shortand ==> Shorthand
./pkg/buildx/build/build.go:1197: Accpet ==> Accept

% codespell --ignore-words-list=intoto,nd,vertexes --skip="*.sum" --write-changes

[jacobwgillespie]

Nice 🧹