Update bug_report.md

Replace master with main, add missing colons to desktop section.

Signed-off-by: philiporlando <[email protected]>

Author: philiporlando

.github/ISSUE_TEMPLATE/bug_report.md

@@ -12,7 +12,7 @@ A clear and concise description of what the bug is.
 
 - [ ] I have checked that this issue has not already been reported.
 - [ ] I have confirmed this bug exists on the latest version of pandera.
-- [ ] (optional) I have confirmed this bug exists on the master branch of pandera.
+- [ ] (optional) I have confirmed this bug exists on the main branch of pandera.
 
 **Note**: Please read [this guide](https://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports) detailing how to provide the necessary information for us to reproduce your bug.
 
@@ -29,8 +29,8 @@ A clear and concise description of what you expected to happen.
 #### Desktop (please complete the following information):
 
  - OS: [e.g. iOS]
- - Browser [e.g. chrome, safari]
- - Version [e.g. 22]
+ - Browser: [e.g. chrome, safari]
+ - Version: [e.g. 22]
 
 #### Screenshots
 If applicable, add screenshots to help explain your problem.