docs: replace `.js` with `.mjs` in links to files

CONTRIBUTING.md

@@ -1,7 +1,7 @@
 ### If you commit changes:
 
 1. Make sure all tests pass.
-2. Run `./benchmark/benchmark.js`, make sure that performance not degraded.
+2. Run `./benchmark/benchmark.mjs`, make sure that performance not degraded.
 3. DON'T include auto-generated browser files to commit.
 
 ### Other things:

README.md

@@ -122,7 +122,7 @@ const md = markdownit({
   linkify:      false,
 
   // Enable some language-neutral replacement + quotes beautification
-  // For the full list of replacements, see https://github.com/markdown-it/markdown-it/blob/master/lib/rules_core/replacements.js
+  // For the full list of replacements, see https://github.com/markdown-it/markdown-it/blob/master/lib/rules_core/replacements.mjs
   typographer:  false,
 
   // Double + single quotes replacement pairs, when typographer enabled,
@@ -258,9 +258,9 @@ const md = markdownit({
 
 You can find all rules in sources:
 
-- [`parser_core.js`](lib/parser_core.js)
+- [`parser_core.mjs`](lib/parser_core.mjs)
-- [`parser_block.js`](lib/parser_block.js)
+- [`parser_block.mjs`](lib/parser_block.mjs)
-- [`parser_inline.js`](lib/parser_inline.js)
+- [`parser_inline.mjs`](lib/parser_inline.mjs)
 
 
 ## Benchmark
@@ -281,7 +281,7 @@ Sample: README.md (7774 bytes)
  > marked x 1,587 ops/sec ±4.31% (93 runs sampled)
 ```
 
-__Note.__ CommonMark version runs with [simplified link normalizers](https://github.com/markdown-it/markdown-it/blob/master/benchmark/implementations/current-commonmark/index.js)
+__Note.__ CommonMark version runs with [simplified link normalizers](https://github.com/markdown-it/markdown-it/blob/master/benchmark/implementations/current-commonmark/index.mjs)
 for more "honest" compare. Difference is ≈1.5×.
 
 As you can see, `markdown-it` doesn't pay with speed for its flexibility.

docs/architecture.md

@@ -48,7 +48,7 @@ The difference is simple:
 - There are special token objects, "inline containers", that have nested tokens.
   These are sequences with inline markup, such as bold, italic, text, etc.
 
-See the [`Token`](https://github.com/markdown-it/markdown-it/blob/master/lib/token.js) class
+See the [`Token`](https://github.com/markdown-it/markdown-it/blob/master/lib/token.mjs) class
 for details about each token's content.
 
 In total, a token stream is:
@@ -66,8 +66,8 @@ intoto an AST.
 
 More details about tokens:
 
-- [`Renderer` source](https://github.com/markdown-it/markdown-it/blob/master/lib/renderer.js)
+- [`Renderer` source](https://github.com/markdown-it/markdown-it/blob/master/lib/renderer.mjs)
-- [`Token` source](https://github.com/markdown-it/markdown-it/blob/master/lib/token.js)
+- [`Token` source](https://github.com/markdown-it/markdown-it/blob/master/lib/token.mjs)
 - [Live demo](https://markdown-it.github.io/) - type your text and click the `debug` tab.
 
 
@@ -179,8 +179,8 @@ And somewhere in between, you can apply additional transformations.
 
 Source code for each chain can be seen in the following files:
 
-- [`parser_core.js`](https://github.com/markdown-it/markdown-it/blob/master/lib/parser_core.js)
+- [`parser_core.mjs`](https://github.com/markdown-it/markdown-it/blob/master/lib/parser_core.mjs)
-- [`parser_block.js`](https://github.com/markdown-it/markdown-it/blob/master/lib/parser_block.js)
+- [`parser_block.mjs`](https://github.com/markdown-it/markdown-it/blob/master/lib/parser_block.mjs)
-- [`parser_inline.js`](https://github.com/markdown-it/markdown-it/blob/master/lib/parser_inline.js)
+- [`parser_inline.mjs`](https://github.com/markdown-it/markdown-it/blob/master/lib/parser_inline.mjs)
 
 Also, you can change output directly in a [`Renderer`](https://markdown-it.github.io/markdown-it/#Renderer) for many simple cases.

support/api_header.md

@@ -88,7 +88,7 @@ const md = markdownit({
   linkify:      false,
 
   // Enable some language-neutral replacement + quotes beautification
-  // For the full list of replacements, see https://github.com/markdown-it/markdown-it/blob/master/lib/rules_core/replacements.js
+  // For the full list of replacements, see https://github.com/markdown-it/markdown-it/blob/master/lib/rules_core/replacements.mjs
   typographer:  false,
 
   // Double + single quotes replacement pairs, when typographer enabled,