Improve documentation to include JNA configuration capabilities

Hi all,

testcontainers appears to be using JNA to perform its magic. By default, JNA writes to /tmp/jna folder and tries to execute something from there.

On some environments, /tmp folder is mounted with noexec flag, which makes the whole process fail.

Could you please add a documentation section where you specify your usage of JNA (maybe it's coming from docker-java?) and adding a note that properties jna.tmpdir and java.io.tmpdir can be used to override the default value?

A sample error that might occur during build with wrong configuration is:

ERROR o.t.d.EnvironmentAndSystemPropertyClientProviderStrategy.test - ping failed with configuration Environment variables, system properties and defaults. Resolved: 
[08:35:13][Step 2/5]     dockerHost=unix:///var/run/docker.sock
[08:35:13][Step 2/5]     apiVersion='{UNKNOWN_VERSION}'
[08:35:13][Step 2/5]     registryUrl='https://index.docker.io/v1/'
[08:35:13][Step 2/5]     registryUsername='xxx'
[08:35:13][Step 2/5]     registryPassword='null'
[08:35:13][Step 2/5]     registryEmail='null'
[08:35:13][Step 2/5]     dockerConfig='DefaultDockerClientConfig[dockerHost=unix:///var/run/docker.sock,registryUsername=xxx,registryPassword=<null>,registryEmail=<null>,registryUrl=https://index.docker.io/v1/,dockerConfigPath=/home/xxx/.docker,sslConfig=<null>,apiVersion={UNKNOWN_VERSION},dockerConfig=<null>]'
[08:35:13][Step 2/5]  due to java.lang.RuntimeException: java.lang.UnsatisfiedLinkError: /tmp/jna-100295547/jna9104525941980512569.tmp: /tmp/jna-100295547/jna9104525941980512569.tmp: failed to map segment from shared object: Operation not permitted
[08:35:13][Step 2/5] 	at org.rnorth.ducttape.timeouts.Timeouts.callFuture(Timeouts.java:68)

And I understand it is not directly your issue, but having a documentation section about it would help others in the future

Thanks and cheers

The issue names no documentation file or test. Start by locating the existing configuration or troubleshooting documentation and confirming whether JNA arrives through docker-java; add the requested JNA usage and tmpdir guidance, including the noexec symptom, then check that the new section renders with the surrounding docs.