Update example install url from try.gogs.io to try.gitea.io (#385)

* Update example install url from try.gogs.io to try.gitea.io

* Ask if issue can be reproduced on try.gitea.io

* Link try.gitea.io to the README

.github/issue_template.md

   - [ ] PostgreSQL
   - [ ] MySQL
   - [ ] SQLite
+- Can you reproduce the bug at https://try.gitea.io:
+  - [ ] Yes (provide example URL)
+  - [ ] No
+  - [ ] Not relevant
 - Log gist:
 
 ## Description

README.md

 
 The goal of this project is to make the easiest, fastest, and most painless way of setting up a self-hosted Git service. With Go, this can be done with an independent binary distribution across **ALL platforms** that Go supports, including Linux, Mac OS X, Windows and ARM.
 
+Want to try it before doing anything else?
+Do it [online](https://try.gitea.io/)!
+
 ## Features
 
 - Activity timeline

templates/install.tmpl

 					</div>
 					<div class="inline required field">
 						<label for="domain">{{.i18n.Tr "install.domain"}}</label>
-						<input id="domain" name="domain" value="{{.domain}}" placeholder="e.g. try.gogs.io" required>
+						<input id="domain" name="domain" value="{{.domain}}" placeholder="e.g. try.gitea.io" required>
 						<span class="help">{{.i18n.Tr "install.domain_helper"}}</span>
 					</div>
 					<div class="inline required field">
 					</div>
 					<div class="inline required field">
 						<label for="app_url">{{.i18n.Tr "install.app_url"}}</label>
-						<input id="app_url" name="app_url" value="{{.app_url}}" placeholder="e.g. https://try.gogs.io" required>
+						<input id="app_url" name="app_url" value="{{.app_url}}" placeholder="e.g. https://try.gitea.io" required>
 						<span class="help">{{.i18n.Tr "install.app_url_helper"}}</span>
 					</div>
 					<div class="inline required field">