[Font Editor]: Changing font weight for section titles
[Font Editor]: Changing font weight for section titles

Issue:
- Font Editor section titles are unusually bold - doesn't fit other heading conventions in the DevTools

Changes:
- change section title font weight to be normal

Before: https://imgur.com/HN64Jqp
After: https://imgur.com/uugug1S

Bug: 1163821
Change-Id: I062ed8efb3101ccb93aa195e13bd993ae4bdc420
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2613795
Reviewed-by: Robert Paveza <7787129de3d0cb4911c68d958db3023863584560@microsoft.com>
Reviewed-by: Mathias Bynens <17a2cbc4e33156874a9862b0f530521117e66a3d@chromium.org>
Commit-Queue: Michael Liao <00d75d81082fdf74688ec453c516b42f7cbf0f40@microsoft.com>

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