update readme

[ci skip]
Shortcut with string values are deprecated
add gem badge

[ci skip]
throw syntax error if you write text after closed tag

issue #333
changes

[ci skip]
Little README correction. [ci skip]

- "enabled enabled" => "enabled"
update readme

[ci skip]
update badge
update readme
improve option docu

[ci skip]
fix readme

[ci skip]
update readme

[ci skip]
require temple 0.6.0
fix readme

[ci skip]
deprecate 2.0.0 incompatible features to make an upgrade easier
add warning for escape_quoted_attrs
changes
better warning
improve warnings
fix splat