doc update; tool update; clean up

Signed-off-by: Martin <Ho-Ro@users.noreply.github.com>

README.md

@@ -15,7 +15,7 @@ to the *International Committee of the Red Cross*.
 [![Downloads of latest release](https://img.shields.io/github/downloads/OpenHantek/OpenHantek6022/latest/total?color=blue)](https://github.com/OpenHantek/OpenHantek6022/releases/latest)
 
 [![GitHub commits since latest release](https://img.shields.io/github/commits-since/OpenHantek/OpenHantek6022/latest?color=lightblue)](https://github.com/OpenHantek/OpenHantek6022/commits/main)
-[![Downloads of latest unstable](https://img.shields.io/github/downloads/OpenHantek/OpenHantek6022/unstable/total?color=lightblue)](https://github.com/OpenHantek/OpenHantek6022/releases/tag/unstable)
+[![Downloads of latest devdrop](https://img.shields.io/github/downloads/OpenHantek/OpenHantek6022/devdrop/total?color=lightblue)](https://github.com/OpenHantek/OpenHantek6022/releases/tag/devdrop)
 
 
 OpenHantek6022 is a free software for **Hantek DSO6022** USB digital signal oscilloscopes that is actively developed on
@@ -134,9 +134,9 @@ If you make small changes to the local source code, it is sufficient to call `ma
 ## Install Prebuilt Binary Packages
 * [![Downloads of latest release](https://img.shields.io/github/downloads/OpenHantek/OpenHantek6022/latest/total?color=blue)](https://github.com/OpenHantek/OpenHantek6022/releases/latest)
 Download Linux (Ubuntu 2004 LTS), Raspberry Pi (Debian stable), FreeBSD (12.1), macOS (Big Sur 11.6) and Windows (Visual Studio 2019) packages for your convenience from the [Releases](https://github.com/OpenHantek/OpenHantek6022/releases) page.
-* [![Downloads of latest unstable](https://img.shields.io/github/downloads/OpenHantek/OpenHantek6022/unstable/total?color=lightblue)](https://github.com/OpenHantek/OpenHantek6022/releases/tag/unstable)
+* [![Downloads of latest devdrop](https://img.shields.io/github/downloads/OpenHantek/OpenHantek6022/devdrop/total?color=lightblue)](https://github.com/OpenHantek/OpenHantek6022/releases/tag/devdrop)
 If you want to follow ongoing development, packages built from a fairly recent commit are available in the rolling
-[unstable release](https://github.com/OpenHantek/OpenHantek6022/releases/tag/unstable).
+[devdrop release](https://github.com/OpenHantek/OpenHantek6022/releases/tag/devdrop).
 *Unstable* does not mean that the program will crash, but that individual features or elements of the GUI may still change.
 * For RPi4 see also [issue #28](https://github.com/OpenHantek/OpenHantek6022/issues/28).
 * These binary packages are built on stable operating system versions and require an up-to-date system.

utils/upload-github-release-assets/upload-github-release-assets.py

@@ -3,7 +3,7 @@
 Upload local files (e.g. RPi installation packages) as assets to a GitHub release.
 It authorizes with the repo token and gets the upload_url for the relevant tag.
 Existing remote files with the same name will be deleted before uploading.
-Defaults to: OpenHantek/OpenHantek6022/releases/tags/unstable
+Defaults to: OpenHantek/OpenHantek6022/releases/tags/devdrop
 '''
 
 #########################
@@ -31,12 +31,12 @@
 	help = f"specify the repository owner, default = '{OWNER}'" )
 ap.add_argument( "-r", "--repo", default = REPO,
 	help = f"specify the repository, default = '{REPO}'" )
-ap.add_argument( "-t", "--tag", default = 'unstable',
-	help = f"specify a tag, default = 'unstable'" )
+ap.add_argument( "-t", "--tag", default = 'devdrop',
+	help = f"specify a tag, default = 'devdrop'" )
 ap.add_argument( "-l", "--latest", action='store_true',
 	help = f"select 'latest' release, overide '-t' or '--tag'" )
-ap.add_argument( "-u", "--unstable", action='store_true',
-	help = f"select 'unstable' release, overide '-t' or '-l'" )
+ap.add_argument( "-d", "--devdrop", action='store_true',
+	help = f"select 'devdrop' release, overide '-t' or '-l'" )
 ap.add_argument( 'files', metavar='FILE', type=str, nargs='*',
 	help = f"file to be uploaded" )
 
@@ -49,8 +49,8 @@
 if options.latest:
 	TAG = 'latest'
 
-if options.unstable:
-	TAG = 'unstable'
+if options.devdrop:
+	TAG = 'devdrop'
 
 files = options.files