chore(netlify): force=true to all redirects (hexojs#1375)

The redirect behavior will be changed since April 7th. Redirects without the forced rules will not work if the file exists for a given path. This pull request adds `force = true` to all `redirects` in `netlify.toml`.

https://community.netlify.com/t/changed-behavior-in-redirects/10084/16
https://docs.netlify.com/configure-builds/file-based-configuration/#redirects

netlify.toml

@@ -8,30 +8,35 @@
   to = "/zh-tw/"
   status = 302
   conditions = {Language = ["zh-tw", "zh-hk"]}
+  force = true
 
 [[redirects]]
   from = "/"
   to = "/zh-cn/"
   status = 302
   conditions = {Language = ["zh", "zh-cn"]}
+  force = true
 
 [[redirects]]
   from = "/"
   to = "/ru/"
   status = 302
   conditions = {Language = ["ru"]}
+  force = true
 
 [[redirects]]
   from = "/"
   to = "/ko/"
   status = 302
   conditions = {Language = ["ko"]}
+  force = true
 
 [[redirects]]
   from = "/"
   to = "/pt-br/"
   status = 302
   conditions = {Language = ["pt-br"]}
+  force = true
 
 [[headers]]
   for = "/*"