Replace (ptext .. sLit) with `text`
1. `text` is as efficient as `ptext . sLit` thanks to the rewrite rules
2. `text` is visually nicer than `ptext . sLit`
3. `ptext . sLit` encourages using one `ptext` for several `sLit` as in:
ptext $ case xy of
... -> sLit ...
... -> sLit ...
which may allocate SDoc's TextBeside constructors at runtime instead
of sharing them into CAFs.