The --speed parameter was announced in each language README's
"Update News" entry dated 2025.11.19 and is already parsed by the
example code in every language ({go,rust,java,swift}/example_onnx.*),
but the "Available Arguments" reference table is missing the row in
4 of the 8 language READMEs. The Python, Node.js, C#, and C++ READMEs
already list it.
Add the missing row in each affected table, verbatim with the wording
already used in the other 4 READMEs:
| --speed | float | 1.05 | Speech speed factor (higher = faster, lower = slower) |
Go uses single-dash to match the surrounding rows in its own table.
