[DOC] Update format specification

[eleanorfrajka]

Description:

Updating the format specification to follow more closely the OceanSITES format, but augmented in places with OG1 format (vocabularies!) and collapsing the creator_*, principal_investigator_* attributes into contributor_*

• Add complete OceanArray format specification (oceanarray_format.rst) building on OceanSITES 1.4 with OG1 enhancements
• Add authentic OceanSITES 1.4 reference manual (oceanSITES_manual.rst) with proper cross-reference labels
• Update documentation index to include both specifications
• Add oceanographic parameter naming resources to development guidelines

Key Features

• Format specification: 9-section comprehensive specification covering file organization, global attributes, dimensions, coordinates, data variables, QC flags,
  and reference tables
• OG1 integration: Incorporates OceanGliders format patterns for contributor metadata and sensor information variables, and time format choices
• Clear deviations: Documents specific differences from OceanSITES (N_LEVELS vs DEPTH dimension, UDUNITS-2 formatting, comma-separated contributors)
• Cross-references: Complete RST label system enabling proper documentation linking between specifications
• Reference tables: Comprehensive units, QC flags, processing levels, and recommended variable name tables

Technical Details

• Uses N_LEVELS dimension instead of DEPTH to reduce pressure/depth confusion
• Follows UDUNITS-2 formatting conventions (spaces, negative exponents, no parentheses)
• Supports comma-separated multi-contributor metadata following OG1 patterns. Note: for institutions with a common in the name, this comma is stripped.
• Maintains OceanSITES compatibility with OS_ filename prefix
• Includes sensor information variables as dimensionless following OG1 structure

Documentation Structure

• oceanarray_format.rst: New comprehensive format specification
• oceanSITES_manual.rst: Complete authentic OceanSITES 1.4 manual for reference