Add introductory section and graphical navigation to CyberOps Dashboard

Enhanced the CyberOps Dashboard with the following updates:
- Added an introductory section on the main frame to describe the purpose of the application.
- Introduced a graphical navigation system using Streamlit buttons within columns for better user experience.
- Data Upload: Allows users to upload CSV files.
- Data Visualization: Enables users to select columns for plotting.
- Analysis Tools: Provides options for combinatorial analysis.
- Maintained core functionality including file upload, data visualization, combinatorial analysis, and grouping/aggregation.
- Ensured compatibility with larger datasets using Dask for efficient data processing.
- Updated the sidebar to support new navigation features and options.

app.py

@@ -27,6 +27,32 @@ def main():
     # Option to select a CSV file
     uploaded_file = st.sidebar.file_uploader("Select a CSV file:", type=["csv"])
 
+    # Main frame for introduction and navigation
+    with st.container():
+        st.subheader("Welcome to CyberOps Dashboard")
+        st.write("""
+            The CyberOps Dashboard is designed to assist cybersecurity professionals in analyzing and visualizing data efficiently.
+            With this tool, you can upload CSV files, visualize data trends, and perform advanced data analysis.
+        """)
+
+        # Navigation section
+        st.subheader("Navigation")
+        st.write("Use the buttons below to navigate to different sections:")
+        col1, col2, col3 = st.columns(3)
+
+        with col1:
+            if st.button("Data Upload"):
+                st.sidebar.file_uploader("Select a CSV file:", type=["csv"])
+
+        with col2:
+            if st.button("Data Visualization"):
+                st.sidebar.selectbox('Select X-axis:', [])
+                st.sidebar.selectbox('Select Y-axis:', [])
+
+        with col3:
+            if st.button("Analysis Tools"):
+                st.sidebar.multiselect('Select columns for combinations:', [])
+
     if uploaded_file:
         @st.cache_data
         def load_csv(file):