Update GET-STARTED.md

docs/GET-STARTED.md

@@ -141,7 +141,7 @@ You have now completed the dependencies installation!
 
 ### Widevine
 
-Wherever you got your Widevine CDM from, its either going to be a single `.wvd` file or a pair of `.bin` and `.pem` files.
+If you have a Widevine CDM key dump, its either going to be a single `.wvd` file or a pair of `.bin` and `.pem` files. \
 In any case, multi-downloader-nx supports both formats. Place them in the `widevine` folder and you are good to go.
 
 The only requirement is that the CDM is a L3 CDM. File type/name does not matter.
@@ -154,8 +154,22 @@ If you have a Playready CDM key dump, you just need to make sure:
 3. Make sure you are using the latest version of shaka-packager from Stratuma, as he has patched it to work with multi-downloader-nx.\
    You can find his releases [here](https://github.com/stratumadev/shaka-packager/releases/latest)
 
-File type does not matter, as multi-downloader-nx supports both `.prd` device files and the `bgroupcert.dat` and `zgpriv.dat` blobs.
+File type does not matter, as multi-downloader-nx supports both `.prd` device files and the `bgroupcert.dat` and `zgpriv.dat` blobs. \
-As long as the above requirements are met and the files are placed in the `playready` folder, you are good to go.
+`.prd` files can be placed into the `playready` folder with whatever name it has.
+
+But if you are using the 2 `.dat` blob files, you need to rename them like so:
+- `.dat` file that is 1.xx KiB -> `bgroupcert.dat`
+- `.dat` file that is 32 bytes -> `zgpriv.dat`
+
+Output form [mediainfo](https://mediaarea.net/en/MediaInfo) can help you identify which file is which.
+```
+bgroupcert.dat
+1.26 KiB
+
+zgpriv.dat
+32.0 Bytes
+```
+Keep in mind that the `bgroupcert.dat` may not always be exactly 1.26 KiB but it should be in the KiB range, while the `zgpriv.dat` will always be 32 bytes.
 
 ## Installation