docs: "APIデザインガイドライン"を追加 (#870) #3104

Job	Run time
actionlint	14s
rust-integration-test-strategy-matrix	1s
rust-lint	4m 10s
rust-unit-test	5m 6s
shellcheck	11s
validate-cargo-lock	20s
build-and-test-java-api (windows-latest)	6m 19s
build-and-test-python-api (windows-latest)	6m 14s
build-and-test-java-api (macos-latest)	2m 43s
build-and-test-python-api (macos-latest)	3m 42s
build-unix-cpp-example (macos-latest, osx-x64-cpu-cpp-shared)	1m 37s
build-and-test-java-api (ubuntu-latest)	2m 44s
build-unix-cpp-example (ubuntu-latest, linux-x64-cpu-cpp-shared)	1m 35s
build-and-test-python-api (ubuntu-latest)	2m 57s
build-windows-cpp-example	3m 56s
c-header	46s
rust-integration-test (macos-12)	2m 2s
rust-integration-test (ubuntu-20.04)	1m 33s
	46m 10s

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