Publish packets to PlatformIO registry

[maxgerhardt]

To make usage of these packages even easier in a platform, the packages should be published to the PlatformIO trusted registry, with pio package publish (and a PlatformIO account of course / previous pio account login)

The package.json in the generated releases is already correct, however one nitpick I'd have is to use more 'traditional' naming. E.g., the OpenOCD package.json has as name field openocd -- (Helper)Tools in PlatformIO have a tool- prefix (toolchains have toolchain- prefix). PlatformIO already has tool-openocd, but more importantly tool-openocd-raspberrypi which is currently used in https://github.com/platformio/platform-raspberrypi. You can choose a unique name here (e.g. tool-openocd-pico or tool-openocd-raspberrypi-earlephilhower), but or also tool-openocd-rasberrypi (PlatformIO can distinguish by owner name, but you will get a warning for the name already being taken at upload).

toolchain-pico for the compiler is fine.

pioasm should be renamed to tool-pioasm though.

tool-mklittlefs doesn't need to uploaded because PlatformIO already has it, same for elf2uf2 (in tool-rp2040tools).

Note that before publishing, issue #4 should be investigated.

[earlephilhower]

@maxgerhardt let me know if I did the pio package publish properly. I published all the files I upload to the release, and it's now a make target so will be automated on future revs.