Translations:Typography refresh/53/en

The stack specified a range of fonts from Helvetica Neue to Arial that are available across all major platforms. Even though Arial is widely used as a default, we need to specify it so there the CSS degradation is predictable. To ensure a reliable experience to users across platforms as best as we can, we decided to include non-free fonts in the stack since many operating systems (such as Windows, MacOS, and iOS) do not have any FOSS fonts installed by default.