Replace all instances of "e.g." with "for example" in documentation

[Copilot]

This PR systematically replaces all instances of "e.g." with "for example" throughout the documentation to improve readability and consistency. The changes maintain proper capitalization based on context:

• Beginning of sentences: "E.g." → "For example"
• Mid-sentence usage: "e.g." → "for example"
• Parenthetical usage: "(e.g." → "(for example"

Changes made:

• 96 files modified across the documentation
• 229 total instances of "e.g." replaced
• All replacements preserve the original meaning and context
• No functional changes to documentation structure or formatting

Examples of changes:

# Before
A graphical representation of query results in Kibana (e.g., a histogram, line graph, pie chart, or heat map).

# After  
A graphical representation of query results in Kibana (for example, a histogram, line graph, pie chart, or heat map).

# Before
E.g. The average of `cpu_time` on an hourly basis.

# After
For example The average of `cpu_time` on an hourly basis.

The replacement was performed using a systematic approach with regex patterns to ensure consistency and accuracy across all affected files.

Fixes #3083.

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