This helps to keep the prelude small and less likely to conflict with
other crates.
- remove widgets module from prelude as the entire module can be just as
easily imported with `use ratatui::widgets::*;`
- move prelude module into its own file
- update examples to import widgets module instead of just prelude
- added several modules to prelude to make it possible to qualify
imports that collide with other types that have similar names
* refactor: add Line type to replace Spans
`Line` is a significantly better name over `Spans` as the plural causes
confusion and the type really is a representation of a line of text made
up of spans.
This is a backwards compatible version of the approach from
https://github.com/tui-rs-revival/ratatui/pull/175
There is a significant amount of code that uses the Spans type and
methods, so instead of just renaming it, we add a new type and replace
parameters that accepts a `Spans` with a parameter that accepts
`Into<Line>`.
Note that the examples have been intentionally left using `Spans` in
this commit to demonstrate the compiler warnings that will be emitted in
existing code.
Implementation notes:
- moves the Spans code to text::spans and publicly reexports on the text
module. This makes the test in that module only relevant to the Spans
type.
- adds a line module with a copy of the code and tests from Spans with a
single addition: `impl<'a> From<Spans<'a>> for Line<'a>`
- adds tests for `Spans` (created and checked before refactoring)
- adds the same tests for `Line`
- updates all widget methods that accept and store Spans to instead
store `Line` and accept `Into<Line>`
* refactor: move text::Masked to text::masked::Masked
Re-exports the Masked type at text::Masked
* refactor: replace Spans with Line in tests/examples/docs
