Development toolkit for rust wasm

The commonly used DOM operations in WASM front-end development are written as functions

```sh

prepend tag to the start of body

prependtobody(tagname:&str,options:&str,inner_html:&str)

append tag to at the end of body

appendtobody(tagname:&str,options:&str,inner_html:&str)

prepend tag to the start of head

prependtohead(tagname:&str,options:&str,inner_html:&str)

append tag to at the end of head

appendtohead(tagname:&str,options:&str,inner_html:&str)

append html to at the end of body

appendhtmltobody(innerhtml:&str)

append html to at the end of head

appendhtmltohead(innerhtml:&str)

append html to at the end of body

appendhtmlbyclassname(classname:&str,innerhtml:&str)

remove element by class name

removeelementbyclassname(class_name:&str)

async get request

get_request(url:&str)->Result

blocking get request

blockinggetrequest(url:&str)->Result ```