Refine 3rdparty/ layout

.gitmodules

@@ -1,3 +1,3 @@
-[submodule "3rdparty/distfiles"]
-	path = 3rdparty/distfiles
+[submodule "3rdparty/_distfiles"]
+	path = 3rdparty/_distfiles
 	url = https://github.com/roc-streaming/distfiles.git

3rdparty/SConscript

@@ -76,7 +76,7 @@ if 'all' in download_dependencies:
 system_dependencies = external_dependencies - download_dependencies
 
 if 'hedley' in vendored_dependencies:
-    env.Append(CPPPATH=['#3rdparty/vendor/hedley'])
+    env.Append(CPPPATH=['#3rdparty/hedley'])
 
 if 'libuv' in system_dependencies:
     conf = Configure(env, custom_tests=env.CustomTests)

scripts/docs/authors.sh

@@ -98,7 +98,7 @@ temp="$(mktemp)"
 cat "$file" > "$temp"
 
 add_contributors "${temp}" "$(basename "$(pwd)")"
-add_contributors "${temp}" "$(basename "$(pwd)")/3rdparty/distfiles"
+add_contributors "${temp}" "$(basename "$(pwd)")/3rdparty/_distfiles"
 add_contributors "${temp}" "roc-go"
 add_contributors "${temp}" "roc-java"
 add_contributors "${temp}" "rt-tests"

scripts/scons/thirdparty.py

@@ -52,7 +52,7 @@ def ThirdParty(
         os.chdir(project_root)
 
         if env.Execute(
-            '%s scripts/build/3rdparty.py %s 3rdparty/distfiles %s %s %s %s %s' % (
+            '%s scripts/build/3rdparty.py %s 3rdparty/_distfiles %s %s %s %s %s' % (
                 quote(env.PythonExecutable()),
                 quote(os.path.relpath(build_root, project_root)),
                 quote(toolchain),