Add a minimal TinyGo guest example

[AndyFerns]

Summary

Adds a new Guest example for TinyGo performing simple logging and KV access

Additions

A TinyGo guest (living under the src/ subdir) that exports run and imports host_log_v2 and db_set from the nx namespace.

• Explicit memory boundary handling (converting Go strings to uint32 pointers/lengths).
• Windows (build.bat) and Linux/macOS (build.sh) build scripts.
• A README detailing requirements, build steps, and TinyGo-specific ABI observations.

notes

• used //go:wasmimport and //go:export directives to keep the WASM ABI clean (no C-esque name mangling)
• compiled with -target wasi to prevent TinyGo from injecting JS-specific runtime hooks (which previously caused gojs::runtime.ticks linking errors)
• skipped optimizations (-opt=0) in the build scripts so users don't strictly need wasm-opt (Binaryen) installed on their machines just to run the example.

Closes #51

[GianIac]

Thanks a lot for the PR! the README is honest about the -target wasi / -opt=0 trade-offs, the Windows + Unix scripts are a nice extra, and using //go:wasmimport / //go:export is exactly the right approach.

A few small things before merge:

Small fixes

• Please add a trailing newline to the new files (all 5 are missing it, some linters/pre-commit hooks complain).
• Could you set the executable bit on build.sh directly in the commit? That way users don't need the chmod +x step from the README. From your side:

  git update-index --chmod=+x examples/guest_tinygo/build.sh

Please add two short notes to the README

• Because of -target wasi, the module also imports wasi_snapshot_preview1 in addition to the nx namespace. Worth calling that out so readers know the import surface is larger than the AssemblyScript/Zig examples.
• stringToWasmPtr takes the address of a heap-allocated []byte and passes it to the host. It works with TinyGo's default GC on wasi, but a one-line caveat about GC / pointer lifetime would be great (or, if you feel like it, switch to a static []byte global — no pressure though).

Not blocking

• Other recent guest examples (AssemblyScript #95, Zig #97) added a CI job that builds and smoke-tests the module. Not asking you to do it here. I'll open a follow-up issue for CI coverage after merge.

Once the small fixes above are in, happy to merge. Thanks again !