IO in Pkl

[havaker]

Commit 6c8f2c49742c184ffb259ed2768cf3ef5704a64d seems to be wrong (Pkl I/O section). Pkl language reference[1][2] specifies that it can do IO (reading files, env vars, sending http requests).

[1] https://github.com/apple/pkl/blob/ce65290aae9c407603a26401d9ac03277bb5de7b/docs/modules/language-reference/pages/index.adoc#resources
[2] https://pkl-lang.org/main/current/language-reference/index.html#resources

[dbohdan]

Thanks. I am going to fix the mistake in a moment.