fix: docs anchors

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit 48c161f):

• https://zksync-web-docs--v-refs-pull-279-merge-f8t9wkbh.web.app
• https://staging-docs-zksync--v-refs-pull-279-merge-n2g1i1ah.web.app

_{(expires Thu, 19 May 2022 19:02:24 GMT)}

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