Use headers to split sections in issue templates

The headers provide better visual differention then just a bold text.

`###` is used as on the WEB interface the H3 header is enough bigger in
comparison to regular text (even bold) and is not too big in general.

.github/ISSUE_TEMPLATE/bug-report.md

@@ -7,19 +7,19 @@ assignees: ''
 
 ---
 
-**The bug**
+### The bug
 A clear and concise description of what the bug is.
 
-**Steps to reproduce**
+### Steps to reproduce
 1. ...
 2. ...
 3. ...
 4. ...
 
-**Expected behavior**
+### Expected behavior
 A clear and concise description of what you expected to happen.
 
-**My environment**
+### My environment
 - `git --version`:  ?
 - `bash --version`: ?
 -  OS: ?

.github/ISSUE_TEMPLATE/chore-report.md

@@ -7,8 +7,8 @@ assignees: ''
 
 ---
 
-**I want to improve ** _please replace with your idea and its benefits_
+### An item to improve
+Please replace with your idea and its benefits.
 
-**I propose this because ** _please replace with your motivation_
-
-**It can be done by ** _please replace this with action items_
+### Technical solution
+Please describe any ideas about the implementation as well as action plan if possible.

.github/ISSUE_TEMPLATE/feature-request.md

@@ -7,14 +7,14 @@ assignees: ''
 
 ---
 
-**A problem/task I want to solve**
+### A problem/task I want to solve
 A clear and concise description of what the problem is. For instance, "I'm always frustrated when ...", "I often need to perform ... and would like to automate it.", etc
 
-**The solution I'd like**
+### The solution I'd like
 A clear and concise description of what you want to happen.
 
-**Considered alternatives**
+### Considered alternatives
 A clear and concise description of any alternative solutions or features you've considered. Please remove if this section is not relevant.
 
-**Additional context**
+### Additional context
 Add any other context about the feature request here. Please remove if you have nothing.