Instruction to reduce disk usage of a node

[mturkia]

Description

Additional documentation. These instructions lower the disk usage of sentries to 20% of the
default configuration. Some of these configurations can safely be used also on a validator.

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For contributor use:

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

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For admin use:

• Added appropriate labels to PR (ex. WIP, R4R, docs, etc)
• Reviewers assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[kinrokinro]

Great, good job!

[fedekunze]

Thanks @mturkia! Can you drop your evmos address on the comments?

[mturkia]

Thanks @mturkia! Can you drop your evmos address on the comments?

evmos1zk8ef40wrhm8z9sqcmfa0zhz8euyyra8lmuesf