Initial checkin of Pika from heckimp

devel-docs/os-support.txt

@@ -0,0 +1,32 @@
+## PIKA's Operating System Support
+
+PIKA is available on a wide range of operating systems.
+As a general rule, we should stop supporting a platform as soon as the
+publisher stops supporting it, or if it is nearly not used anymore.
+
+There is no accurate rule though, and it also mostly depends on what the
+developers maintaining PIKA for this platform will decide.
+
+### GNU/Linux, *BSD…
+
+Until PIKA 3.0 release, Debian 12 "bookworm" stable will be our baseline target.
+I.e. that we can bump a minimum dependency version only if it is in Debian
+bookworm.
+
+After PIKA 3.0 release, we might get back to depend on Debian Testing.
+
+### macOS
+
+Compatibility with 10.13 and over.
+
+Hardware:
+* x86_64 (Intel)
+* ARM 64-bit (Apple Silicon)
+
+### Windows
+
+Windows 10 and over.
+
+Hardware:
+* x86 32 and 64-bit
+* ARM 64-bit (experimental)