docs: Add Core Library to introduction section of the Sway book #20508

Job	Run time
build-sway-examples	1m 37s
build-sway-lib-core	4m 20s
build-sway-lib-std	1m 22s
get-fuel-core-version	49s
build-reference-examples	4m 42s
forc-fmt-check-panic	1m 57s
forc-fmt-check-sway-examples	3m 47s
forc-fmt-check-sway-lib-core	4m 7s
forc-fmt-check-sway-lib-std	1m 2s
build-forc-doc-sway-lib-std	1m 57s
build-forc-test-project	11m 18s
cargo-build-workspace	9m 13s
build-mdbook	4m 46s
cargo-clippy	4m 39s
cargo-fmt-check	14s
cargo-run-e2e-test-evm	2m 50s
cargo-run-e2e-test-midenvm	8m 41s
cargo-test-lib-std	2m 51s
cargo-toml-fmt-check	15s
check-sdk-harness-test-suite-compatibility	48s
forc-run-benchmarks	3m 48s
cargo-test-sway-lsp	10m 41s
cargo-test-workspace	5m 18s
cargo-unused-deps-check	10m 6s
forc-pkg-fuels-deps-check	13s
forc-unit-tests	1m 57s
pre-publish-check	0s
cargo-run-e2e-test	12m 12s
cargo-run-e2e-test-release	13m 20s
cargo-test-forc-debug	4m 18s
cargo-test-forc-client	3m 16s
notify-slack-on-failure	1s
build-publish-master-image	0s
publish	0s
build-publish-release-image	0s
Build and upload forc binaries to release	0s
	2h 16m 25s

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