Fix ProcInst node level. Change condition to check for DocumentNode 

Merge PR #123 

Bump `golang.org/x/net` from 0.7.0 to 0.33.0 close #110

update deps `github.com/antchfx/xpath` from v1.3.1 to v1.3.2 

update package `github.com/antchfx/xpath` from v1.3.0 to v1.3.1 

github.com/antchfx/xpath from 1.2.4 to 1.3.0 

Merge PR #107 

Add new example code 

update github.com/antchfx/xpath from v1.2.3 to v1.2.4 

update https://github.com/antchfx/xpath to v1.2.3