Restructure influxdb3 /plugins for step-by-step clarity

[MeelahMe]

**Objective:

To revise the /plugins section to be more structured and step-by-step than it is now. The goal is to make it easier for users to understand how plugins work, how to configure them, and how to build or extend them—especially for those who are new to InfluxDB 3 or plugin-based architectures.

What the feature does and why it’s useful

• Transforms the current /plugins documentation into a more linear, guided experience
• Helps users understand the purpose, setup, and customization of plugins
• Reduces confusion and improves onboarding by clearly walking through key workflows
• How to use it

Once updated, users should be able to:

• Understand what plugins are and how they fit into the system
• Follow clear, step-by-step instructions to enable, configure, and test plugins
• Extend or write their own plugins, if applicable

part of #5857
closes #5951

[Copilot]

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (2)

content/shared/v3-core-plugins/extended-plugin-api.md:189

• [nitpick] The placeholder 'METHOD' and 'PARAMETERS' may confuse users. Consider either replacing these with concrete examples or adding a clarifying comment that indicates these are placeholders.

influxdb3_local.cache.METHOD(PARAMETERS)

content/shared/v3-core-plugins/extended-plugin-api.md:95

• [nitpick] Ensure that converting a float with no decimal component to an integer and appending '.0' meets the intended behavior and formatting requirements. Verify this behavior remains consistent with all usage scenarios.

self.fields[key] = f"{int(value)}.0" if value % 1 == 0 else str(value)

[Copilot]

Pull Request Overview

This PR restructures the InfluxDB 3 plugins documentation to provide a more step-by-step and guided experience for users. Key changes include:

• Adding a new shared extended plugin API documentation file with detailed code samples.
• Updating the enterprise and core plugin extension files to source from the shared API document.
• Refining menu naming and presentation for clarity.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

File	Description
content/shared/extended-plugin-api.md	New, detailed documentation for the shared plugin API, complete with code examples and usage guidelines.
content/influxdb3/enterprise/plugins.md	Minor update to the menu name for stylistic consistency.
content/influxdb3/enterprise/extend-plugin.md	New documentation file extending plugins by sourcing shared API content.
content/influxdb3/core/extend-plugin.md	New documentation file extending plugins by sourcing shared API content, with slight naming differences.

Comments suppressed due to low confidence (2)

content/influxdb3/core/extend-plugin.md:7

• [nitpick] The menu name here differs from the enterprise version ('Extend plugins'); consider aligning the naming across both files for consistency.

    name: Extended plugins

content/influxdb3/enterprise/plugins.md:8

• [nitpick] The change to 'Processing engine' appears intended for stylistic consistency; please confirm that this aligns with the overall documentation style.

    name: Processing engine and Python plugins

accident! sorry

[Copilot]

Pull Request Overview

This PR restructures the plugins documentation for InfluxDB 3, making the content more linear and easier for new users to follow. The key changes include the addition of a comprehensive shared plugin API guide with code examples, a renaming update for the enterprise plugins menu, and new extend-plugin documents linking to the shared API content.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

File	Description
content/shared/extended-plugin-api.md	Added detailed shared API documentation with code examples
content/influxdb3/enterprise/plugins.md	Updated menu item naming for clarity
content/influxdb3/enterprise/extend-plugin.md	New extend-plugin file importing shared API content
content/influxdb3/core/extend-plugin.md	New extended plugins file for the core docs linking the shared API source

Comments suppressed due to low confidence (1)

content/shared/extended-plugin-api.md:109

• Consider swapping the order of escaping backslashes and quotes (i.e. escape backslashes first) to ensure that quotes are not double escaped. This can help avoid potential issues with improperly escaped string values.

escaped_value = value.replace('"', '\"').replace('\\', '\\\\')

[jstirnaman]

Change to active voice.