Give Programs/ one rule: a directory per kind, nothing loose

Five .asm files sat at the top of Programs/ beside six directories, with
nothing to say which a new file should join - and hello.asm, which is the
native assembler's first target and named in sixteen places, looked like a
stray.

    Programs/
      Examples/     what you read to learn: hello, printHello, inputTest,
                    replCalculator, and Fibonacci, primeSieve and gameOfLife
                    as sets of their own
      Libraries/    included by name, no entry point of their own
      Loader/       loader.asm, and the loadable program it reads
      CosmOS/       the system, its applications and its assembler
      testPrograms/ what 'make test' drives

Loader/ is the one worth explaining. loader.asm is not a demonstration: it
reads a program off a disk, puts the two pieces where the header asks, and
jumps to the entry. CosmOS grew out of it and does the same thing as one of
its commands. It is kept because backward compatibility with the simplest
version of the system is a standing goal, and it was sitting loose next to
the demos as though it were one.

Programs/loadable/ was a directory holding one file called hello.asm - a
third thing of that name, and the name said nothing about why it was there.
It is Loader/loadable.asm now, beside the loader that reads it.

Every reference moved with them: the makefile's program list, twelve
manifest lines, makedisks.sh, native.sh, and four paths across the README
and both manuals. Verified by deleting both build directories and running
the whole suite from nothing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW

Programs/Examples/Fibonacci/16bitFibonacci.asm

@@ -0,0 +1,77 @@
+; A Fibonacci number generating program that uses two bytes to store the value.
+
+#Include print.asm
+
+#Program
+start:
+  ; Swap ValueB and ValueA.
+  ; First, store ValueA on the stack.
+  SETD ValueA
+  LDA
+  PSHA
+  INCD
+  LDA
+  PSHA
+  ; Now copy ValueB into AB.
+  SETD ValueB
+  LDA ; High byte
+  INCD
+  LDB ; Low byte
+  ; Now save it back to ValueA
+  SETD ValueA
+  STA ; High byte
+  INCD
+  STB ; Low byte.
+  ; Now retrieve value A from the stack and store it in ValueB.
+  POPB
+  POPA
+  SETD ValueB
+  STA
+  INCD
+  STB
+  ; Print ValueA.
+  SETD ValueA
+  LDA
+  CALL printByteHex
+  INCD
+  LDA
+  CALL printByteHex
+  CALL blankSpace
+  ; Now add ValueA and ValueB, and store the result in ValueA.
+  ; Add the low bytes of ValueA and ValueB
+  SETD ValueB
+  INCD
+  LDA
+  SETD ValueA
+  INCD
+  LDB
+  CCF
+  ADD
+  ; Store the result in ValueA.
+  STQ
+  ; Now add the high bytes of ValueA and ValueB.
+  DECD
+  LDB
+  SETD ValueB
+  LDA
+  ADD
+  ; If this addition overflows, we're done.
+  BRC end
+  ; Otherwise, store the result in ValueA.
+  SETD ValueA
+  STQ
+  ; And branch back to the beginning of the loop.
+  BRI start
+ end:
+  CALL lineFeed
+  HALT
+
+#Data
+
+ValueA:
+; Low byte, high byte.
+0x00 0x01
+
+ValueB:
+; Low byte, high byte.
+0x00 0x00