[Tips] Markdown cross reference

Note: csdn jump md does not support, you can use [toc]the build directory

1. Markdown refers to a certain title of the same file

[title](#title)

1. Using #selected chapters
2. Change uppercase letters to lowercase
3. Remove the brackets （） 。 .and other special characters
4. Spaces with -alternative

2. Markdown references another file

[title](./dir/file.md)

1. You can use relative file paths
2. Other matters needing attention are the same as above

3. Markdown refers to a certain title of another file

[title](./dir/file.md#title)

1. You can use relative file paths
2. Other matters needing attention are the same as above