Remove useless BEGIN/END delimiters

They made sense when the script was bigger, now they delimit basically
the whole script.  Also "built part" is not accurate since the part is
not built--it only happens to contain lot of macros.

src/bin/app.skel

@@ -2,10 +2,6 @@
 
 . "$(shellfu-get path)" || exit 3
 
-#
-# =====BEGIN BUILT PART=====
-#
-
 #shellcheck disable=SC2034
 {
     SATURNIN_APP_CODENAME="__MKIT_PROJ_CODENAME__"
@@ -31,10 +27,6 @@ SATURNIN_CONF_PATH="$(
         "__SATURNIN_SHARE__/ini.d"
 )"
 
-#
-# =====END BUILT PART=====
-#
-
 export SATURNIN_CONF_PATH SHELLFU_PATH PRETTY_USAGE \
        SATURNIN_CACHE_HOME SATURNIN_CONFIG_HOME SATURNIN_DATA_HOME