Add doc

Author: KelvinChung2000

docs/source/Building fabric.rst

@@ -14,7 +14,7 @@ completed.
 
 #. Create a new project
 
-   .. prompt:: bash FABulous>
+   .. prompt:: bash
 
         FABulous -c demo
 

docs/source/Usage.rst

@@ -103,17 +103,28 @@ Install FABulous with "editable" option:
 Building Fabric and Bitstream
 -----------------------------
 
+We offer two ways to run the FABulous flow, either via the FABulous Shell or directly supplying the commands via the command line (similar to Vivado Batch mode).
+
+To use the FABulous Shell, you can run the following command:
 
 .. code-block:: console
 
    (venv)$ FABulous -c <name_of_project>
    (venv)$ FABulous <name_of_project>
 
    # inside the FABulous shell
-   FABulous> load_fabric
    FABulous> run_FABulous_fabric
    FABulous> run_FABulous_bitstream user_design/sequential_16bit_en.v
 
+
+To run the FABulous flow directly from the command line, you can use the following commands:
+.. code-block:: console
+
+   (venv)$ FABulous -c <name_of_project>
+   (venv)$ FABulous <name_of_project> -p "run_FABulous_fabric; run_FABulous_bitstream user_design/sequential_16bit_en.v"
+
+
+
 .. note::
 
   You will probably receive a warning for the FASM package like the following: