Add link on the website to the google form for problem/benchmark submission. (#136)

Author: kvdblom

docs/header.html

@@ -22,5 +22,5 @@
 <h2>OPL &ndash; Optimisation problem library</h2>
 
 <p>
-Submit problems and corrections on <a target="_blank" href="https://github.com/OpenOptimizationOrg/OPL/">GitHub</a> with pull requests / issues, or by email: <a href="mailto:koen.van.der.blom@cwi.nl" itemprop="email">koen.van.der.blom@cwi.nl</a>
+Submit problems and corrections on <a target="_blank" href="https://github.com/OpenOptimizationOrg/OPL/">GitHub</a> with pull requests / issues, through the <a target="_blank" href="https://docs.google.com/forms/d/e/1FAIpQLSehQp24AuFAH2j9jizDhq8K_BYgNGMKXWTMu6s-2RwEJrK59Q/viewform">Google form</a>, or by email: <a href="mailto:koen.van.der.blom@cwi.nl" itemprop="email">koen.van.der.blom@cwi.nl</a>
 </p>

docs/index.html

@@ -22,7 +22,7 @@
 <h2>OPL &ndash; Optimisation problem library</h2>
 
 <p>
-Submit problems and corrections on <a target="_blank" href="https://github.com/OpenOptimizationOrg/OPL/">GitHub</a> with pull requests / issues, or by email: <a href="mailto:koen.van.der.blom@cwi.nl" itemprop="email">koen.van.der.blom@cwi.nl</a>
+Submit problems and corrections on <a target="_blank" href="https://github.com/OpenOptimizationOrg/OPL/">GitHub</a> with pull requests / issues, through the <a target="_blank" href="https://docs.google.com/forms/d/e/1FAIpQLSehQp24AuFAH2j9jizDhq8K_BYgNGMKXWTMu6s-2RwEJrK59Q/viewform">Google form</a>, or by email: <a href="mailto:koen.van.der.blom@cwi.nl" itemprop="email">koen.van.der.blom@cwi.nl</a>
 </p>
 <table class="dataframe display compact display styled-table" id="problems">
   <thead>