Rename the rel/ directory to config/ by default

doc/src/guide/eunit.asciidoc

@@ -65,7 +65,7 @@ to be passed to `erl` when running EUnit tests. For example,
 you can load the 'vm.args' and 'sys.config' files:
 
 [source,make]
-EUNIT_ERL_OPTS = -args_file rel/vm.args -config rel/sys.config
+EUNIT_ERL_OPTS = -args_file config/vm.args -config config/sys.config
 
 === Usage
 

doc/src/guide/releases.asciidoc

@@ -124,7 +124,7 @@ Your release was upgraded!
 There is a *workaround* to get the semver value which is
 generated by Relx based on VCS history.
 
-Create a file 'rel/version' with only one line inside:
+Create a file 'config/version' with only one line inside:
 
 [source,erlang]
 {{ release_version }}
@@ -133,7 +133,7 @@ Add/Update the `overlay` section of your `relx.config`:
 
 [source,erlang]
 {overlay, [
-    {template, "rel/version", "version"}
+    {template, "config/version", "version"}
 ]}.
 
 When you run `make rel` it creates the file '$(RELX_OUTPUT_DIR)/example/version'

plugins/bootstrap.mk

@@ -94,8 +94,8 @@ endef
 define bs_relx_config
 {release, {$p_release, "1"}, [$p, sasl, runtime_tools]}.
 {extended_start_script, true}.
-{sys_config, "rel/sys.config"}.
-{vm_args, "rel/vm.args"}.
+{sys_config, "config/sys.config"}.
+{vm_args, "config/vm.args"}.
 endef
 
 define bs_sys_config
@@ -441,14 +441,14 @@ bootstrap-rel:
 ifneq ($(wildcard relx.config),)
 	$(error Error: relx.config already exists)
 endif
-ifneq ($(wildcard rel/),)
-	$(error Error: rel/ directory already exists)
+ifneq ($(wildcard config/),)
+	$(error Error: config/ directory already exists)
 endif
 	$(eval p := $(PROJECT))
 	$(verbose) $(call core_render,bs_relx_config,relx.config)
-	$(verbose) mkdir rel/
-	$(verbose) $(call core_render,bs_sys_config,rel/sys.config)
-	$(verbose) $(call core_render,bs_vm_args,rel/vm.args)
+	$(verbose) mkdir config/
+	$(verbose) $(call core_render,bs_sys_config,config/sys.config)
+	$(verbose) $(call core_render,bs_vm_args,config/vm.args)
 
 new-app:
 ifndef in

test/plugin_bootstrap.mk

@@ -204,8 +204,8 @@ bootstrap-rel: build clean
 	$i "Check that all bootstrapped files exist"
 	$t test -f $(APP)/Makefile
 	$t test -f $(APP)/relx.config
-	$t test -f $(APP)/rel/sys.config
-	$t test -f $(APP)/rel/vm.args
+	$t test -f $(APP)/config/sys.config
+	$t test -f $(APP)/config/vm.args
 ifdef LEGACY
 	$t test -f $(APP)/src/$(APP).app.src
 endif