[Keyboard] Add str.merro60 pcb (#17097)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Ryan <fauxpark@gmail.com>
Co-authored-by: Alexander Lee <aclee3@CGHan-Macbook-2015.local>
Co-authored-by: chalex <chlxbsmt@gmail.com>

keyboards/chlx/str_merro60/readme.md

@@ -0,0 +1,21 @@
+# str.merro60
+
+str.merro60 PCB
+
+A standard 60% format keyboard pcb with USB-C and unified daughterboard compatibility.
+Has modified cutouts to allow usage of certain tray mount cases into gummy gasket o-ring mount.
+Has RGB underglow.
+
+* Keyboard Maintainer: [Alexander Lee](https://github.com/gaclee3b)
+* Hardware Supported: chlx PCB str.merro60.1.1
+
+Enter bootloader mode by any of the following options -
+- When unplugged, holding the top-left key (typically ESC) while plugging in the keyboard
+- When plugged in, pressing and releasing the reset button on the pcb bottom behind the CAPSLOCK / A-key region
+- When plugged in, shorting out the two reset metal contacts near the spacebar switch location (NOT the spacebar switch pin holes)
+
+Make example for this keyboard (after setting up your build environment):
+
+    make chlx/str_merro60:default
+
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).