Documentation updates: Explanation section rewrites and docstring updates

[jbrossman]

This pull request makes several improvements to the documentation build configuration for the project. The main changes include expanding the set of external fallback references for InfrastructureSystems types and functions, restructuring and adding new documentation pages for better organization and coverage, and removing the now-obsolete enumerated types API documentation.

Documentation improvements and organization:

• Expanded the ExternalFallbacks in docs/make.jl to include additional InfrastructureSystems types and functions such as add_supplemental_attribute!, remove_supplemental_attribute!, ComponentUUIDs, PiecewiseLinearData, SupplementalAttributeManager, SystemData, TimeSeriesManager, and more, improving cross-referencing in docstrings.
• Restructured the documentation navigation in docs/make.jl by splitting the "add additional data to a component" section into multiple focused pages, and added new how-to guides for unit system conversions, transformer impedance conversion, and using subsystems.
• Removed the api/enumerated_types.md page and its reference from the documentation navigation, as well as the "transformer_per_unit_models.md" and "enumerated_types.md" entries, reflecting a cleanup and update of outdated or redundant content. [1] [2] [3]

These changes enhance the usability and maintainability of the documentation by providing more comprehensive references and a clearer, more organized structure.## Description

This PR updates and tightens documentation content and cross-references, with a focused migration of enumerated type documentation from the standalone API page into the scoped enum docstrings in src/definitions.jl.

In addition to the broader docstring and docs cleanup work already in this PR, the latest updates:

• moved enum tables/content into the corresponding scoped enum docstrings,
• removed repeated enum-name headers in those docstrings,
• replaced old subsection references (e.g., @ref pm_list) with direct enum docstring references (e.g., @ref PrimeMovers) across docs/generated docs,
• removed docs/src/api/enumerated_types.md,
• updated docs/make.jl to remove the old enumerated-types page from navigation.

No new functionality was introduced; these are documentation and reference-structure updates.

Related Issue

This is follow-up documentation work aligned with the existing documentation improvement scope in this PR.

Closes #1504
Closes #1457
Closes #1448

New Structs

Not applicable — no new structs were added.

[codecov]

Codecov Report

❌ Patch coverage is 83.87097% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 84.15%. Comparing base (0650c45) to head (6e722c0).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
src/models/components.jl	33.33%	2 Missing ⚠️
src/models/cost_function_timeseries.jl	0.00%	1 Missing ⚠️
src/models/generation.jl	50.00%	1 Missing ⚠️
src/models/static_models.jl	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1635      +/-   ##
==========================================
+ Coverage   84.13%   84.15%   +0.02%     
==========================================
  Files         204      204              
  Lines       10540    10536       -4     
==========================================
- Hits         8868     8867       -1     
+ Misses       1672     1669       -3     

Flag	Coverage Δ
unittests	84.15% <83.87%> (+0.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/PowerSystems.jl	0.00% <ø> (ø)
src/base.jl	88.95% <100.00%> (+0.18%)	⬆️
src/definitions.jl	100.00% <ø> (ø)
src/get_components_interface.jl	80.00% <ø> (ø)
src/impedance_correction.jl	100.00% <ø> (ø)
src/models/HybridSystem.jl	75.64% <100.00%> (ø)
src/models/OuterControl.jl	64.70% <100.00%> (ø)
src/models/RoundRotorExponential.jl	86.66% <100.00%> (ø)
src/models/RoundRotorQuadratic.jl	86.66% <100.00%> (ø)
src/models/SalientPoleExponential.jl	64.28% <100.00%> (ø)
... and 24 more

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[kdayday]

@jbrossman I haven't taken a look yet, but FYI, about figures there's a different file path to get it to show up locally versus on github ("../" vs. "../../" or vice versa). We will want whichever one gets it to show up on the github Preview, so don't worry about it if it doesn't show up locally

[Copilot]

Pull request overview

Copilot reviewed 93 out of 135 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (4)

src/subsystems.jl:1

• Typo in the error message string: subystems → subsystems. This message can surface to users, so it should be corrected.
  src/models/static_models.jl:1
• error(ArgumentError(...)) throws an ErrorException (stringifies the ArgumentError) rather than throwing the ArgumentError itself. Use throw(ArgumentError(...)) so callers can reliably catch ArgumentError and so the exception type matches the message.
  docs/src/how_to/use_subsystems.md:1
• This admonition is currently commented out with leading #, so it will render as literal text instead of a !!! note block. Remove the # prefixes and indent the body under !!! note to make Documenter render the note correctly.
  docs/src/tutorials/working_with_time_series.jl:1
• The previous explicit page anchor (@id tutorial_time_series) was removed. Relying on title-based @ref targets is more fragile (title changes break links). Consider restoring a stable @id on the header (even if you also link by title) to keep references resilient.