btop: add page; bpytop: move to `common`, update page (#10425)

pages/common/bpytop.md

@@ -1,6 +1,7 @@
 # bpytop
 
-> Display dynamic real-time information about running processes with graphs. Similar to `gtop` and `htop`.
+> A resource monitor that shows information about the CPU, memory, disks, network and processes.
+> A Python version of `bashtop`.
 > More information: <https://github.com/aristocratos/bpytop>.
 
 - Start `bpytop`:

pages/common/btop.md

@@ -0,0 +1,13 @@
+# btop
+
+> A resource monitor that shows information about the CPU, memory, disks, network and processes.
+> A C++ version of `bpytop`.
+> More information: <https://github.com/aristocratos/btop>.
+
+- Start `btop`:
+
+`btop`
+
+- Start `btop` with the specified settings preset:
+
+`btop --preset {{0..9}}`