update docs

.gitignore

@@ -1,8 +1,4 @@
-################################################################################
-# This .gitignore file was automatically created by Microsoft(R) Visual Studio.
-################################################################################
-
-/build
+/build
 /dist
 /include/Eigen
 *.pyc
@@ -17,3 +13,5 @@ enwiki-1000.txt
 /html/
 .vscode/
 *.pyd
+examples/*
+!examples/*.py

document/document_header.html

@@ -10,8 +10,10 @@
 <a class="homelink" rel="home" title="tomotopy Home" href="/tomotopy" style="display:block; font-size:2em; font-weight:bold; color:#555; padding-bottom:.5em; border-bottom:1px solid silver;"> <img src="/tomotopy/tomoto.png" alt="" style="height:1.5em;"> tomotopy </a>
 <a id='lang-en' href="../en/index.html">English</a> <a id='lang-kr' href="../kr/index.html">한국어</a> 
 <div id="version-link">
-<span>v0.7.1</span>
+<span>v0.8.1</span>
 <ul>
+	<li><a href='/tomotopy/v0.8.1/en'>v0.8.1</a></li>
+	<li><a href='/tomotopy/v0.8.0/en'>v0.8.0</a></li>
 	<li><a href='/tomotopy/v0.7.1/en'>v0.7.1</a></li>
 	<li><a href='/tomotopy/v0.7.0/en'>v0.7.0</a></li>
 	<li><a href='/tomotopy/v0.6.2/en'>v0.6.2</a></li>