Remove install.txt and readme.txt (#9521)

* Remove install.txt and readme.txt

* Refactor tests that use readme.txt

* Tests open own source code

tests/dummy.txt

@@ -0,0 +1 @@
+Just a simple text for test

tests/misc/treadln.nim

@@ -5,7 +5,7 @@ var
   inp: File
   line: string
 
-if open(inp, "readme.txt"):
+if open(inp, "tests/misc/treadln.nim"):
   while not endOfFile(inp):
     line = readLine(inp)
     echo("#" & line & "#")

tests/stdlib/tmemlines.nim

@@ -1,5 +1,5 @@
 import memfiles
-var inp = memfiles.open("readme.txt")
+var inp = memfiles.open("tests/stdlib/tmemlines.nim")
 for line in lines(inp):
   echo("#" & line & "#")
 close(inp)

tests/stdlib/tmemlinesBuf.nim

@@ -1,5 +1,5 @@
 import memfiles
-var inp = memfiles.open("readme.txt")
+var inp = memfiles.open("tests/stdlib/tmemlinesBuf.nim")
 var buffer: TaintedString = ""
 for line in lines(inp, buffer):
   echo("#" & line & "#")

tests/stdlib/tmemslices.nim

@@ -1,5 +1,5 @@
 import memfiles
-var inp = memfiles.open("readme.txt")
+var inp = memfiles.open("tests/stdlib/tmemslices.nim")
 for mem in memSlices(inp):
   if mem.size > 3:
     echo("#" & $mem & "#")

tests/threads/threadex.nim

@@ -1,5 +1,5 @@
 discard """
-  outputsub: "All rights reserved."
+  outputsub: "Just a simple text for test"
 """
 
 type
@@ -28,7 +28,7 @@ proc consume() {.thread.} =
 proc produce() {.thread.} =
   prodId = getThreadId()
   var m: TMsg
-  var input = open("readme.txt")
+  var input = open("tests/dummy.txt")
   var line = ""
   while input.readLine(line):
     m.data = line

tests/vm/tslurp.nim

@@ -4,8 +4,8 @@ template getScriptDir(): string =
   parentDir(instantiationInfo(-1, true).filename)
 
 const
-  relRes = slurp"../../readme.txt"
-  absRes = slurp(parentDir(parentDir(getScriptDir())) / "readme.txt")
+  relRes = slurp"./tslurp.nim"
+  absRes = slurp(getScriptDir() / "tslurp.nim")
 
 echo relRes
 echo absRes