refactor: restructure monorepo for clean portfolio layout

- Move timesfm-forecast into apps/ directory
- Flatten Udacity portfolio projects from deep URL-encoded paths
  into data-engineering/01-XX numbered directories
- Remove old My-Data-Engineering-Portifolio/ parent directory
- Rewrite root README.md: professional overview with badges,
  project table, and repo structure diagram
- Create data-engineering/README.md with per-project descriptions
- Add README.md for 02-cassandra-modeling (was missing)
- Add README.md for 05-airflow-pipelines (was missing)
- Normalize capstone readme.md -> README.md
- Update .gitignore: add *.cfg, *.env, *.zip, *.sas7bdat,
  Jupyter checkpoints, IDE dirs; remove uv.lock exclusion
- Add dwh.cfg.example and dl.cfg.example credential templates
- Untrack real credential files (dwh.cfg, dl.cfg)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

data-engineering/03-cloud-data-warehouse/etl.py

@@ -0,0 +1,45 @@
+import configparser
+import psycopg2
+from sql_queries import copy_table_queries, insert_table_queries
+
+
+def load_staging_tables(cur, conn):
+    '''Copy the staging tables to S3 bucket: staging_events and staging_songs'''
+    for query in copy_table_queries:
+        try:
+            cur.execute(query)
+            conn.commit()
+            print(query + ' - Done!')
+        except:
+            print(query + ' - Fail!')
+            pass
+
+def insert_tables(cur, conn):
+    '''Load the values from staging table into the tables: songplays, users, songs, artists, time'''
+    for query in insert_table_queries:
+        try:
+            cur.execute(query)
+            conn.commit()
+            print(query + ' - Done!')
+        except:
+            print(query + ' - Fail!')
+            pass
+
+def main():
+    '''Read AWS requirements from dwh.cfg file'''
+    config = configparser.ConfigParser()
+    config.read('dwh.cfg')
+
+    '''Connect to the Redshift cluster'''
+    conn = psycopg2.connect("host={} dbname={} user={} password={} port={}".format(*config['CLUSTER'].values()))
+    cur = conn.cursor()
+    
+    '''Run above functions according to sql_queries.py'''
+    load_staging_tables(cur, conn)
+    insert_tables(cur, conn)
+
+    conn.close()
+
+
+if __name__ == "__main__":
+    main()