add idsp crate

README.md

@@ -1190,6 +1190,7 @@ Work in progress drivers. Help the authors make these crates awesome!
 1. [gcode](https://github.com/Michael-F-Bryan/gcode-rs): A gcode parser for no-std applications - [![crates.io](https://img.shields.io/crates/v/gcode.svg)](https://crates.io/crates/gcode)
 1. [gdbstub](https://crates.io/crates/gdbstub): zero-allocation, pure Rust implementation of the GDB Remote Serial Protocol - [![crates.io](https://img.shields.io/crates/v/gdbstub.svg)](https://crates.io/crates/gdbstub)
 1. [heapless](https://crates.io/crates/heapless): provides `Vec`, `String`, `LinearMap`, `RingBuffer` backed by fixed-size buffers  - ![crates.io](https://img.shields.io/crates/v/heapless.svg)
+1. [idsp](https://crates.io/crates/idsp): integer DSP algorithms (trigonometry, filtering, PLL...) tuned for precision and speed - ![crates.io](https://img.shields.io/crates/v/idsp.svg)
 1. [ieee802154](https://crates.io/crates/ieee802154): Partial implementation of the IEEE 802.15.4 standard - ![crates.io](https://img.shields.io/crates/v/ieee802154.svg)
 1. [infrared](https://crates.io/crates/infrared): infrared remote control library for embedded rust - ![crates.io](https://img.shields.io/crates/v/infrared.svg)
 1. [intrusive-collections](https://crates.io/crates/intrusive-collections): intrusive (non-allocating) singly/doubly linked lists and red-black trees - ![crates.io](https://img.shields.io/crates/v/intrusive-collections.svg)