Examples restructure

[MabezDev]

Our examples are not great. Some are fine to keep, but I think they can be organized better. I propose the following structure for examples/.

├── async # executor specific examples
├── ble # trouble examples
├── interrupt # probably just GPIO example at this point
├── ota
├── peripheral
│   ├── spi # collapse the various SPI examples into one spi and one spi dma example, we can use multiple bins for this where the dependencies won't change (i.e no deciphering of Cargo.toml to copy the example)
│   │   └── bin/
│   │   │    └── spi.rs
│   │   │    └── spi_dma.rs
│   │   └── src/
│   │   └── Cargo.toml
│   ├── touch
│   │   └── Cargo.toml
│   └── twai
│       └── Cargo.toml
├── tls # we need an mbedtls example and probably a rustls one
└── wifi
└── esp-now

Example conversion

When converting to the example structure above, we need to consider the following:

• Examples should be projects this means, Cargo.toml and any other files required
• I think generating these projects from esp-generate is the best foot forward
• Handling //% FEATURES //% CHIPS from examples
  • I think this is straight forward, we can parse the toml and if the chip feature exists the example supports it.
  • FEATURES is no longer required because the features will be enabled in the example Cargo.toml