add eggpu doc

Author: jessicawwen

docs/_sources/eggpu.rst.txt

@@ -15,6 +15,7 @@ EGGPU is engineered with a three-layer architecture:
 * **Computation Layer**: Implemented in CUDA C/C++, this layer primarily executes the GPU-based network analysis functions, including betweenness centrality, k-core centrality, and SSSP.
 
 .. image:: eggpu_architecture.png
+   :align: center
 
 Installation
 +++++++++++++

docs/eggpu.html

@@ -92,7 +92,7 @@ <h2>Overview<a class="headerlink" href="#overview" title="Permalink to this head
 <li><p><strong>Middleware Layer</strong>: Constructed in C++, this layer shares memory space with the Computation Layer and serves as the binding agent. It also provides a graph container responsible for graph loading, storage, and format conversion.</p></li>
 <li><p><strong>Computation Layer</strong>: Implemented in CUDA C/C++, this layer primarily executes the GPU-based network analysis functions, including betweenness centrality, k-core centrality, and SSSP.</p></li>
 </ul>
-<img alt="_images/eggpu_architecture.png" src="_images/eggpu_architecture.png" />
+<img alt="_images/eggpu_architecture.png" class="align-center" src="_images/eggpu_architecture.png" />
 </section>
 <section id="installation">
 <h2>Installation<a class="headerlink" href="#installation" title="Permalink to this heading"></a></h2>