Fixed the documentation in Example Tools

[p4lik4ri]

After installing tquic and building the example tools with:

cargo build --release --all

running the QUIC server as documented:

./tquic_server -c cert.crt -k cert.key -l 127.0.0.1:8443

Leads to the following error:

TlsFail("use certificate chain file(\"cert.crt\") failed")

Cause

The generated binaries are placed in:

./target/release/

However, the example certificates (cert.crt and cert.key) are located in:

./src/tls/testdata/

When running the binary from a different directory, the relative paths cert.crt and cert.key cannot be resolved, which causes TLS initialization to fail.

Proposed Fix

Update the documentation to use the correct certificate paths:

./tquic_server -c ../../src/tls/testdata/cert.crt -k ../../src/tls/testdata/cert.key -l 127.0.0.1:8443 

Alternatively, instruct users to run the binary from the project root directory or copy the certificates into the same directory as the executable.

This ensures the server can properly locate and load the TLS certificate and private key.