Docs: the README, JSPR, Cloudloop, testing

README says what the module adds to Ground Control's library and what it
works around, and how to use it. JSPR.md is the protocol as the library
speaks it, from its source, with its surprises. CLOUDLOOP.md is account
to first message, from WII6's IRIDIUM.md. TESTING.md is the levels, the
rig, and what has passed: Python, native_sim, an ESP32-S3 and an STM32U5
against the fake, and free checks against a real 9704.

CHANGELOG.md

@@ -0,0 +1,21 @@
+# Changes
+
+## 0.1.0, 2026-10-09
+
+The first release.
+
+- Ground Control's RockBLOCK 9704 library v1.0.1, pinned untouched, built
+  as a Zephyr module with a serial port on the devicetree node's UART.
+- One worker thread owns the library; it sleeps until a request or a byte
+  from the modem arrives.
+- `<rb9704/rb9704.h>`: begin, end, power, send, info, signal, each with a
+  timeout; callbacks for a sent message, a received one, the signal and
+  the provisioning; a status snapshot.
+- Provisioning asked again when the library's cached answer is missing a
+  topic, or after the modem refuses one.
+- The `rock7,rockblock-9704` binding with optional power, enable and
+  booted pins.
+- The `rb9704` shell command and the shell sample, with overlays for
+  native_sim, NUCLEO-U575ZI-Q, XIAO ESP32S3 and ESP32-S3-DevKitC.
+- `python/`: the `rb9704` command line, the `rb9704-fake` fake modem, and
+  tests for the Python binding, native_sim, boards and a real modem.