Markdown code blocks part 5 (#20236)

No logic was added, just a few more `*.md` files have been migrated.

doc/nep1.md

@@ -49,7 +49,7 @@ Spacing and Whitespace Conventions
   Not all editors support automatic alignment of code sections, and re-aligning
   long sections of code by hand can quickly become tedious.
 
-  .. code-block:: nim
+    ```nim
     # This is bad, as the next time someone comes
     # to edit this code block, they
     # must re-align all the assignments again:
@@ -60,6 +60,7 @@ Spacing and Whitespace Conventions
       CalId*       = int
       LongLong*    = int64
       LongLongPtr* = ptr LongLong
+    ```
 
 
 Naming Conventions
@@ -69,7 +70,7 @@ Naming Conventions
   camelCase with the exception of constants which **may** use PascalCase but
   are not required to.
 
-  .. code-block:: nim
+    ```nim
     # Constants can start with either a lower case or upper case letter.
     const aConstant = 42
     const FooBar = 4.2
@@ -79,6 +80,7 @@ Naming Conventions
     # Types must start with an uppercase letter.
     type
       FooBar = object
+    ```
 
   For constants coming from a C/C++ wrapper, ALL_UPPERCASE are allowed, but ugly.
   (Why shout CONSTANT? Constants do no harm, variables do!)
@@ -89,41 +91,45 @@ Naming Conventions
   that will be used the most, add the suffixes to the pointer variants only. The
   same applies to C/C++ wrappers.
 
-  .. code-block:: nim
+    ```nim
     type
       Handle = object # Will be used most often
         fd: int64
       HandleRef = ref Handle # Will be used less often
+    ```
 
 - Exception and Error types should have the "Error" or "Defect" suffix.
 
-  .. code-block:: nim
+    ```nim
     type
       ValueError = object of CatchableError
       AssertionDefect = object of Defect
       Foo = object of Exception # bad style, try to inherit CatchableError or Defect
+    ```
 
 - Unless marked with the `{.pure.}` pragma, members of enums should have an
   identifying prefix, such as an abbreviation of the enum's name.
 
-  .. code-block:: nim
+    ```nim
     type
       PathComponent = enum
         pcDir
         pcLinkToDir
         pcFile
         pcLinkToFile
+    ```
 
 - Non-pure enum values should use camelCase whereas pure enum values should use
   PascalCase.
 
-  .. code-block:: nim
+    ```nim
     type
       PathComponent {.pure.} = enum
         Dir
         LinkToDir
         File
         LinkToFile
+    ```
 
 - In the age of HTTP, HTML, FTP, TCP, IP, UTF, WWW it is foolish to pretend
   these are somewhat special words requiring all uppercase. Instead treat them
@@ -230,12 +236,13 @@ Coding Conventions
   are required. Use a procedure's implicit `result` variable whenever possible.
   This improves readability.
 
-  .. code-block:: nim
+    ```nim
     proc repeat(text: string, x: int): string =
       result = ""
 
       for i in 0..x:
         result.add($i)
+    ```
 
 - Use a proc when possible, only using the more powerful facilities of macros,
   templates, iterators, and converters when necessary.
@@ -252,15 +259,16 @@ Conventions for multi-line statements and expressions
 - Tuples which are longer than one line should indent their parameters to
   align with the parameters above it.
 
-  .. code-block:: nim
+    ```nim
     type
       LongTupleA = tuple[wordyTupleMemberOne: int, wordyTupleMemberTwo: string,
                          wordyTupleMemberThree: float]
+    ```
 
 - Similarly, any procedure and procedure type declarations that are longer
   than one line should do the same thing.
 
-  .. code-block:: nim
+    ```nim
     type
       EventCallback = proc (timeReceived: Time, errorCode: int, event: Event,
                             output: var string)
@@ -268,13 +276,15 @@ Conventions for multi-line statements and expressions
     proc lotsOfArguments(argOne: string, argTwo: int, argThree: float,
                          argFour: proc(), argFive: bool): int
                         {.heyLookALongPragma.} =
+    ```
 
 - Multi-line procedure calls should continue on the same column as the opening
   parenthesis (like multi-line procedure declarations).
 
-  .. code-block:: nim
+    ```nim
     startProcess(nimExecutable, currentDirectory, compilerArguments
                  environment, processOptions)
+    ```
 
 Miscellaneous
 -------------
@@ -290,18 +300,20 @@ Miscellaneous
 
   use this:
 
-  .. code-block:: nim
+    ```nim
     let a = """
     foo
     bar
     """
+    ```
 
   instead of:
 
-  .. code-block:: nim
+    ```nim
     let a = """foo
     bar
     """
+    ```
 
 - A getter API for a private field `foo` should preferably be named `foo`, not `getFoo`.
   A getter-like API should preferably be named `getFoo`, not `foo` if: