Add dye and microscope search to Algolia autocomplete

[tlambert03]

This commit closes #327 by adding dyes and microscopes to the comprehensive Algolia search bar.

Backend changes:

• Added DyeIndex and MicroscopeIndex to proteins/index.py
• Added url property to Dye model (links to spectra viewer)
• Added url and owner_name properties to Microscope model
• Updated base.html template to expose dyeIndex and microscopeIndex

Frontend changes:

• Updated algolia.js to initialize dye and microscope indices
• Added autocomplete sources for dyes (3 per page) and microscopes (2 per page)
• Updated highlightHits to support manufacturer, part, slug, and owner_name fields
• Added placeholder icon images for dye and microscope results

Dyes link to the spectra viewer (/spectra/) and microscopes link to the microscope detail page (/microscope//).

Note: Algolia indices need to be populated using Django management commands: python manage.py algolia_reindex --model Dye python manage.py algolia_reindex --model Microscope