You can customise the excerpt (the text displayed below each post on the homepage) using the excerpt-separator. Here’s how you can do so!
Add excerpt_separator: <!--more--> to the frontmatter of your blog post.
Insert this <!--more--> at where you would like the excerpt to cut off in your blog post.
This follows Jekyll’s recommended way of managing excerpts.
See this post or the “Introducing Tale” post.