DOCS-194 - Update ignorePatterns, exclude patterns, robots.txt

[kimsauce]

Purpose of this pull request

Updates ignorePatterns, exclude patterns, robots.txt so that /reuse/ files are blocked from indexing

Select the type of change

• Minor Changes - Typos, formatting, slight revisions
• Update Content - Revisions, updating sections
• New Content - New features, sections, pages, tutorials
• Site and Tools - .clabot, version updates, maintenance, dependencies, new packages for the site (Docusaurus, Gatsby, React, etc.)

Ticket (if applicable)

https://sumologic.atlassian.net/browse/DOCS-194

[jpipkin1]

@kimsauce, the build-and-deploy check is failing:

Error: Error: Docusaurus could not load module at path "/home/runner/work/sumologic-documentation/sumologic-documentation/docusaurus.config.js"

re-requested review