change theme in AndroidManifest.xml
prepare layouts for main screen in landscape and portrait modes
add file zoologo.jpg
add empty layouts aboutzoo.xml, options.xml, sightseeing.xml
add files layout-land/main.xml, res/values/styles.xml
fix code in layouts, styles and strings.xml;
rename files main.xml, aboutzoo.xml, options.xml, sightseeing.xml
add file colors.xml
Folder .idea is no longer tracked
Merge pull request #4 from ampatalas/android

Create welcome screen
Fixed invalid layout used in MainActivity
Merge remote-tracking branch 'remotes/upstream/android' into android
Dropped appcombat and gridlayout libraries from repository and projects, properly merged with upstream (theme).