Use relative links in documentation

Author: jyn514

src/doc/src/reference/profiles.md

@@ -67,16 +67,20 @@ amount of debug information included in the compiled binary.
 
 The valid options are:
 
-* `0`, `false`, or `"none"`: no debug info at all
-* `"line-directives-only"`: line info directives only. For the nvptx* targets this enables [profiling](https://reviews.llvm.org/D46061). For other use cases, `line-tables-only` is the better, more compatible choice.
+* `0`, `false`, or `"none"`: no debug info at all, default for [`release`](#release)
+* `"line-directives-only"`: line info directives only. For the nvptx* targets this enables [profiling]. For other use cases, `line-tables-only` is the better, more compatible choice.
 * `"line-tables-only"`: line tables only. Generates the minimal amount of debug info for backtraces with filename/line number info, but not anything else, i.e. no variable or function parameter info.
 * `1` or `"limited"`: debug info without type or variable-level information. Generates more detailed module-level info than `line-tables-only`.
-* `2`, `true`, or `"full"`: full debug info
+* `2`, `true`, or `"full"`: full debug info, default for [`dev`](#dev)
+
+For more information on what each option does see `rustc`'s docs on [debuginfo].
 
 You may wish to also configure the [`split-debuginfo`](#split-debuginfo) option
 depending on your needs as well.
 
 [`-C debuginfo` flag]: ../../rustc/codegen-options/index.html#debuginfo
+[debuginfo]: ../../rustc/codegen-options/index.html#debuginfo
+[profiling]: https://reviews.llvm.org/D46061
 
 #### split-debuginfo