Update Day-04-Linux Commands and Permissions Basics.md

Update Day-06-Monitoring-and-Logging-Basics.md

Fix heading format for AI applications section

Update Day-10-REST-API-Design-Basics.md

Update Day-05-Databases-SQL-vs-NoSQL.md

Update Day-05 Linux Users Groups + Shell Scripting.md

Fix header formatting in Linux Commands document

Update Day-03-Linux-Fundamentals-for-DevOps.md

Update Day-10-Classification-Metrics.md

Update Day-13-Feature-Scaling-Normalization-Standardization.md

Fix formatting of L1 Regularization section header

Clean up formatting in APIs and REST Basics document

Fix header formatting for REST API section

Update Day-08-Latency-vs-Throughput.md

Update Day - 02- Machine Learning Basics.md