update issue template (#4991)

* update issue template

* try to add comments

.github/ISSUE_TEMPLATE/bug_report.md

@@ -3,9 +3,50 @@ name: "\U0001F41B Bug Report"
 about: Create a bug report to help us improve DVC
 ---
 
-## Bug Report
+# Bug Report
 
-### Please provide information about your setup
+<!--
+## Issue name
+
+Issue names must follow the pattern `command: description` where the command is the dvc command that you are trying to run. The description should describe the consequence of the bug. 
+
+Example: `repro: doesn't detect input changes`
+-->
+
+## Description
+
+<!--
+A clear and concise description of what the bug is.
+-->
+
+### Reproduce
+
+<!--
+Step list of how to reproduce the bug
+-->
+
+<!--
+Example:
+
+1. dvc init
+2. Copy dataset.zip to the directory
+3. dvc add dataset.zip
+4. dvc run -d dataset.zip -o model ./train.sh
+5. modify dataset.zip
+6. dvc repro
+-->
+
+### Expected
+
+<!--
+A clear and concise description of what you expect to happen.
+-->
+
+### Environment information
+
+<!--
+This is required to ensure that we can reproduce the bug.
+-->
 
 **Output of `dvc version`:**
 
@@ -15,4 +56,6 @@ $ dvc version
 
 **Additional Information (if any):**
 
+<!--
 If applicable, please also provide a `--verbose` output of the command, eg: `dvc add --verbose`.
+-->