Address code quality review issues

@katbow raised a number of useful comments in #15 that need to be addressed:
- [ ] Custom tachyons classes `mw3-5` are not clear. My reasoning was that it's between `mw3` and `mw4` which are 4rem and 8rem respectively. It's actually way closer to `mw3` at 4.2rem but I thought mw3-1 would look even stranger. Both have issues :woman_shrugging:
- [x] Pipes should always start with a pure value - [see comment](https://github.com/dwyl/library/pull/15/files/b03abae0c4769c754104523d875e826354bda1cd#r145371306)
- [x] There's a typo in the placeholder text on the search input.
- [x] Move logic from the book component to component_view