• instead of Must (which panics) use functions that return errors and that function should return an error
• instead of hardcoded "templates/*.html" pass it as function parameter

This code can be shortened to

// import 
// 	htmlTmpl "html/template"
// 	textTmpl "text/template"

type TextTemplateRenderer struct {
	Templates *textTmpl.Template
}

func (t *TextTemplateRenderer) Render(w io.Writer, name string, data interface{}, c Context) error {
	return t.Templates.ExecuteTemplate(w, name, data)
}

type HTMLTemplateRenderer struct {
	Templates *htmlTmpl.Template
}

func (t *HTMLTemplateRenderer) Render(w io.Writer, name string, data interface{}, c Context) error {
	return t.Templates.ExecuteTemplate(w, name, data)
}

and use as

	e.Renderer = &echo.HTMLTemplateRenderer{
		Templates: template.Must(template.ParseGlob("templates/*.html")),
	}

(I'm new in both of Go, and Echo.)
When I tried it as a test, I used my own repository and imported it, not compiled.
So I don't know why it returns an error.
This is a recommendation, this is an idea that you could implement, an idea that will make it a little bit more beginner-friendly, as the current way of middleware is not a very beginner-friendly way to make a simple app.
Thanks for reading,
@IsusRamzy

I've allowed edits by maintainers, so you could implement it the right way.