docs: fix app.toml links

[gibson042]

Description

Fixes links to Running a Node: Configuring the Node Using app.toml and config.toml (many of which were using a probably-outdated #configuring-the-node-using-apptoml page anchor).

Author Checklist

I have...

• included the correct docs: prefix in the PR title
• targeted the correct branch (see PR Targeting)
• [not applicable] provided a link to the relevant issue or specification
• followed the documentation writing guidelines
• reviewed "Files changed" and left comments if necessary
• confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct docs: prefix in the PR title
• confirmed all author checklist items have been addressed
• confirmed that this PR only changes documentation
• reviewed content for consistency
• reviewed content for thoroughness
• reviewed content for spelling and grammar
• tested instructions (if applicable)

[julienrbrt]

Thanks!