Fix issue in Writing Web Applications https://go.dev/doc/articles/wiki/

Technical Discussion
1

Found out there is a small mistake in Writing Web Applications - The Go Programming Language

With this web server running, a visit to http://localhost:8080/view/test should show a page titled “test” containing the words “Hello world”.

Should be

With this web server running, a visit to http://localhost:8080/view/TestPage should show a page titled “test” containing the words “Hello world”.

Otherwise you get this error

2024/05/26 15:01:32 http: panic serving [::1]:52401: runtime error: invalid memory address or nil pointer dereference
goroutine 42 [running]:
net/http.(*conn).serve.func1()
        /usr/local/go/src/net/http/server.go:1898 +0xbe
panic({0x612ee40?, 0x62f4a50?})
        /usr/local/go/src/runtime/panic.go:770 +0x132
main.viewHandler({0x6173ff0, 0xc0001be620}, 0xc0001aab30?)
        /Users/pcam/DEV/GO/GOWIKI/wiki.go:32 +0x96
net/http.HandlerFunc.ServeHTTP(0x6300130?, {0x6173ff0?, 0xc0001be620?}, 0x607961a?)
        /usr/local/go/src/net/http/server.go:2166 +0x29
net/http.(*ServeMux).ServeHTTP(0x5ed40d9?, {0x6173ff0, 0xc0001be620}, 0xc0001ba480)
        /usr/local/go/src/net/http/server.go:2683 +0x1ad
net/http.serverHandler.ServeHTTP({0xc0001946c0?}, {0x6173ff0?, 0xc0001be620?}, 0x6?)
        /usr/local/go/src/net/http/server.go:3137 +0x8e
net/http.(*conn).serve(0xc0001986c0, {0x6174458, 0xc00007ccf0})
        /usr/local/go/src/net/http/server.go:2039 +0x5e8
created by net/http.(*Server).Serve in goroutine 1
        /usr/local/go/src/net/http/server.go:3285 +0x4b4
3

It actually says in the article:

Let’s create some page data (as test.txt), compile our code, and try serving a wiki page.
Open test.txt file in your editor, and save the string “Hello world” (without quotes) in it.