format issues in online manual

[BariumOxide13716]

Details

I spotted a few format issues in the online manual, for example:

for out_hr_npz/out_dm_npz, there are two trademarks in the description,
for dm_to_rho, there is one trademark after "DM",
and for dft_functional, the description "for example, ‘dft_functional=‘LDA_X_1D_EXPONENTIAL+LDA_C_1D_CSC’." contains some unexpected primes.

Besides, the link to the website of the LIBXC keywords redirects me to an unrelated website. Maybe we can use https://libxc.gitlab.io/functionals/ to replace the link.

Have you read the online manual http://abacus.deepmodeling.com/en/latest/

• Yes, I have read the online manual.

Task list for Issue attackers (only for developers)

• Identify the specific section of the documentation with the issue.
• Investigate the issue and determine the root cause.
• Research best practices and potential solutions for the identified issue.
• Update the documentation to address the issue, following the suggested improvement.
• Ensure the updated documentation adheres to the project's documentation standards.
• Test the updated documentation to ensure it is clear and accurate.
• Review and incorporate any relevant feedback from users or developers.
• Publish the updated documentation and notify the issue reporter.

[mohanchen]

Thanks for your suggestions, we will try to fix the issues.