shardtree: Add `ShardTree::insert_frontier` #428

	name: CI checks

	on: [push, pull_request]

	jobs:
	test:
	name: Test on ${{ matrix.os }}
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: [ubuntu-latest, windows-latest, macOS-latest]
	steps:
	- uses: actions/checkout@v3
	- name: Run tests
	run: cargo test --all-features --verbose --workspace
	- name: Verify working directory is clean
	run: git diff --exit-code

	bitrot:
	name: Bitrot check
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	# Build benchmarks to prevent bitrot
	- name: Build benchmarks
	run: cargo build --workspace --benches --all-features

	doc-links:
	name: Intra-doc links
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- run: cargo fetch
	# Requires #![deny(rustdoc::broken_intra_doc_links)] in crates.
	- name: Check intra-doc links
	run: cargo doc --workspace --document-private-items

	fmt:
	name: Rustfmt
	timeout-minutes: 30
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: Check formatting
	run: cargo fmt --all -- --check

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