Resolve "Sample Weighting System - weight sample data"

Description

Weighting data sheet to insert soil sample data or TDR data and receive an averaged water content.

Related Issue

Closes #46 (closed)

Proposed Changes

• Add weighting functions to neptoon
• Make example sheet

Testing

• Calculatee D86
• Calculate R86
• Apply vertical average
• Apply horizontal average

Checklist

• I have tested the changes thoroughly
• I have updated the relevant documentation
• I have added necessary comments and explanations in the code
• I have considered backward compatibility, if applicable
• I have reviewed the code changes myself