Don't inline all keyframes

[theKashey]

Sample code from critters

// detect used keyframes
            if (decl.property === 'animation' || decl.property === 'animation-name') {
              // @todo: parse animation declarations and extract only the name. for now we'll do a lazy match.
              const names = decl.value.split(/\s+/);
              for (let j = 0; j < names.length; j++) {
                const name = names[j].trim();
                if (name) criticalKeyframeNames.push(name);
              }
            }