Fix building from source docs to ref AppWorkPath (#8567)

The current source docs reference AppWorkDir instead of AppWorkPath

docs/content/doc/installation/from-source.en-us.md

@@ -118,12 +118,12 @@ launched manually from command line, it can be killed by pressing `Ctrl + C`.
 ./gitea web
 ```
 
-## Changing the default CustomPath, CustomConf and AppWorkDir
+## Changing the default CustomPath, CustomConf and AppWorkPath
 
 Gitea will search for a number of things from the `CustomPath`. By default this is
 the `custom/` directory in the current working directory when running Gitea. It will also
 look for its configuration file `CustomConf` in `$CustomPath/conf/app.ini`, and will use the
-current working directory as the relative base path `AppWorkDir` for a number configurable
+current working directory as the relative base path `AppWorkPath` for a number configurable
 values.
 
 These values, although useful when developing, may conflict with downstream users preferences.
@@ -134,7 +134,7 @@ using the `LDFLAGS` environment variable for `make`. The appropriate settings ar
 
 * To set the `CustomPath` use `LDFLAGS="-X \"code.gitea.io/gitea/modules/setting.CustomPath=custom-path\""`
 * For `CustomConf` you should use `-X \"code.gitea.io/gitea/modules/setting.CustomConf=conf.ini\"`
-* For `AppWorkDir` you should use `-X \"code.gitea.io/gitea/modules/setting.AppWorkDir=working-directory\"`
+* For `AppWorkPath` you should use `-X \"code.gitea.io/gitea/modules/setting.AppWorkPath=working-path\"`
 
 Add as many of the strings with their preceding `-X` to the `LDFLAGS` variable and run `make build`
 with the appropriate `TAGS` as above.