README: Update to current state of affairs.

Replaces outdated information with more up-to-date/generic, fixing
typos and formatting issues on the way.

Signed-off-by: Paul Sokolovsky <[email protected]>

Author: pfalcon

README.md

@@ -2,10 +2,11 @@
 
 This project is to replace the previous Yocto based SDK with a new framework for
 building the Zephyr SDK using [crosstool-ng](https://crosstool-ng.github.io/).
+(Some tools are still built using Yocto/Bitbake).
 
-The repository consists of configurations for the various architectures (not
-fully tests) and a script that builds on Linux (x86_64) and Mac in a consistent
-way, apply patches where needed.
+The repository consists of configurations for the various architectures (not all
+fully tested) and a script that builds on Linux (x86_64) and Mac in a consistent
+way, applying patches where needed.
 
 Currently we build the following toolchains:
 - i586
@@ -26,28 +27,30 @@ To build for any of the above, run:
 ./go.sh <arch>
 ```
 
-Production builds are done using the script in `.shippable.yml` which
-identifies some packages you'll need to have installed for the above
-command to work.
+Production builds are done using the scripts in `.buildkite/` and
+`.github/workflows/` which identify some packages you'll need to
+have installed for the above command to work.
 
 When building locally be aware that `./go.sh` is written assuming it's
 invoked in a pristine workspace.  That means if you pull an update of
-this repository `./go.sh` will not update the `crosstool-ng` source and
-rebuild the `bin/ct-ng` utility to match the update configuration.  This
+this repository `./go.sh` will not update the `crosstool-ng` source or
+rebuild the `bin/ct-ng` utility to match the updated configuration.  This
 can produce very confusing results.
 
 ## Released Binaries packages
 
-Pre-built binaries releases of the SDK are made and currently only available for
-an x86_64 Linux host environment.  The releases can be found here:
+Pre-built binary releases of the SDK are made for a few OSes and host
+architectures. They can be found here:
 
 https://github.com/zephyrproject-rtos/sdk-ng/releases
 
 ## PR Builds
 
 Successfull PR builds will get posted here:
 
-https://builds.zephyrproject.org/zephyrproject-rtos/sdk-ng/<PR NUMBER>/zephyr-sdk-<VERISON>-setup.run
+```
+https://builds.zephyrproject.org/zephyrproject-rtos/sdk-ng/<PR_NUMBER>/zephyr-sdk-<VERSION>-setup.run
+```
 
 ## Release Process
 
@@ -57,5 +60,5 @@ To release a new SDK:
   0.11.0-beta1 etc.
 - On https://github.com/zephyrproject-rtos/sdk-ng/releases, create the release
   tag and add the release information.
-- One the release is created, CI will build the SDK image and will upload it to
+- Once the release is created, CI will build the SDK image and will upload it to
   the release page.